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Les interventions pour prévenir les grossesses non désirées chez les adolescents

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Referencias

References to studies included in this review

Aarons 2000 {published data only}

Aarons SJ, Jenkins RR, Raine TR, El‐Khorazaty MN, Woodward KM, Williams RL. Postponing sexual intercourse among urban junior high school students ‐ a randomized controlled evaluation. Journal of Adolescent Health 2000;27:236‐47.

Allen 1997 {published data only}

Allen JP, Phillber S, Herring S, Kupermine GP. Preventing teen pregnancy and academic failure; experimental evaluation of a developmentally based approach. Child Development 1997;64(4):729‐42.

Baird 2010 {published data only}

Baird S, Chirwa E, McIntosh C, Özler B. The short‐term impacts of a schooling conditional cash transfer program on the sexual behavior of young women. Health Economics 2010;19:55‐68.

Basen‐Engquist 2001 {published data only}

Basen‐Engquist K, Coyle KK, Parcel GS, Kirby D, Banspach SW, Carvajal SC, et al. Schoolwide effects of a multi‐component HIV, STD, and pregnancy prevention program for high school students. Health Education & Behaviour 2001;28(2):166‐85.

Black 2006 {published data only}

Black MM, Bentley ME, Papas MA, Oberlander S, Teti LO, McNary S, et al. Delaying second births among adolescent mothers: a randomized, controlled trial of a home‐based mentoring program. Pediatrics 2006;118:1087‐99.

Blake 2001 {published data only}

Blake SM, Simkin L, Ledsky R, Perkins C, Calabrese JM. Effects of a parent‐child communications intervention on young adolescents' risk for early onset of sexual intercourse. Family Planning Perspectives 2001;33(2):52‐61.

Bonell 2013 {published data only}

Bonell C, Maisey R, Speight S, Purdon S, Keogh P, Wollny I, et al. Randomized controlled trial of ‘teens and toddlers’: a teenage pregnancy prevention intervention combining youth development and voluntary service in a nursery. Journal of Adolescence 2013;36:859‐70.

Borgia 2005 {published data only}

Borgia P, Marinacci C, Schiifano P, Perruci CA. Is peer education the best approach for HIV prevention in school? Findings from a randomized controlled trial. Journal of Adolescent Health 2005;36:508‐16.

Cabezon 2005 {published data only}

Cabezon C, Vigil P, Rojas I, Leiva ME, Riquelme R, Aranda W, et al. Adolescent pregnancy prevention: an abstinence‐centred randomized controlled intervention in a Chilean public high school. Journal of Adolescent Health 2005;36:64‐9.

Clark 2005 {published data only}

Clark LF, Miller KS, Nagy SS, Avery J, Roth DL, Liddon N, et al. Adult identity mentoring: reducing sexual risk for African American seventh grade students. Journal of Adolescent Health 2005;37:337‐47.

Coyle 1999 {published data only}

Coyle KK, Basen‐Engquist KM, Kirby DB, Parcey GS, Banspach SW, Collins JL, et al. Safer Choices: Long‐term impact of a multi‐component school‐based HIV, other STD and pregnancy program‐a randomized controlled trial. Unpublished data1999.

Coyle 2004 {published data only}

Coyle KK, Kirby DB, Marin BV, Gomez CA, Gregorich SE. Draw the line/respect the line: a randomized trial of a middle school intervention to reduce sexual risk behaviors. American Journal of Public Health 2004;94:843‐51.

Coyle 2006 {published data only}

Coyle KK, Kirby DB, Robin LE, Banspach SW, Baulmer E, Glassman JR. ALL4YOU! A randomized trial of an HIV, other STDs, and pregnancy prevention intervention for alternative school students. AIDS Education and Prevention 2006;18(3):187‐203.

Diclemente 2004 {published data only}

Diclemente RJ, Wingood GM, Harrington KF, Lang DL, Davies SL, Hook EW, et al. Efficacy of an HIV prevention intervention for African American girls. JAMA 2004;292(2):171‐9.

Dilorio 2006 {published data only}

Dilorio C, Resnicow K, McCarty F, De AK, Dudley WN, Wang DT, et al. Keepin' it R.E.A.L! Results of a Mother‐Adolescent HIV prevention program. Nursing Research 2006;55(1):43‐51.

Dilorio 2007 {published data only}

Dilorio C, McCarty F, Resnicow K, Lehr S, Denzmore P. REAL Men: A group‐randomized trial of an HIV prevention intervention for adolescent boys. American Journal of Public Health 2007;97:1084‐9.

Downs 2004 {published data only}

Downs JS, Murray PJ, Bruine de Bruin W, Penrose J, Palmgren C, Fischhoff B. Interactive video behaviour intervention to reduce adolescent females' STD risk: a randomized controlled trial. Social Science & Medicine 2004;59:1561‐72.

Eisen 1990 {published data only}

Eisen M, Zellman GL, McAlister AL. Evaluating the impact of a theory‐based sexuality and contraceptive education program. Family Planning Perspectives 1990;22(6):261‐71.

Fawole 1999 {published data only}

Fawole IO, Azuzu MC, Oduntan SO, Brieger WR. A school‐based AIDS education programme for secondary school students in Nigeria: a review of effectiveness. Health Education Research Theory & Practice 1999;14(5):675‐83.

Ferguson 1998 {published data only}

Ferguson SL. Peer counselling in a culturally specific adolescent pregnancy prevention program. Journal of Health Care for the Poor and Underserved 1998;9(3):323‐33.

Graham 2002 {published data only}

Graham A, Moore L, Sharp D, Diamond I. Improving teenagers' knowledge of emergency contraception: cluster randomized controlled trial of a teacher led intervention. BMJ 2002;324:1179‐85.

Guilamo‐Ramos 2011b {published data only}

Guilamo‐Ramos V, Bouris A, Jaccard J, Gonzalez B, McCoy W, Aranda D. A parent‐based intervention to reduce sexual risk behavior in early adolescence: building alliances between physicians, social workers, and parents. Journal of Adolescent Health 2011;48:159‐63.

Henderson 2007 {published data only}

Henderson M, Wight D, Raab GM, Abraham C, Parkes, Scott S, et al. Impact of a theoretically based sex education programme (SHARE) delivered by teachers on NHS registered conceptions and terminations: final results of cluster randomised trial. BMJ 2007;334:133‐8.

Herceg‐Brown 1986 {published data only}

Herceg‐Brown R, Furstenberg FF, Shea J, Harris KM. Supporting teenager's use of contraceptives: a comparison of clinic services. Family Planning Perspectives 1986;18(9):61‐6.

Howard 1990 {published data only}

Howard M, McCabe JB. Helping teenagers postpone sexual involvement. Family Planning Perspectives 1990;22(1):21‐7.

Jemmott 1998 {published data only}

Jemmott JB, Jemmott LS, Fong GT. Abstinence and safer sex HIV risk‐reduction interventions for African American adolescents. JAMA 1998;279(19):1259‐536.

Jemmott 2005 {published data only}

Jemmott JB, Jemmott LS, Braverman PK, Fong GT. HIV/STD risk reduction interventions for African American and Latino adolescent girls at an adolescent medicine clinic. Archives of Pediatrics and Adolescent Medicine 2005;159:440‐9.

Jemmott 2010 {published data only}

Jemmott JB, Jemmott LS, Fong GT, Morales KH. Effectiveness of an HIV/STD risk‐reduction intervention for adolescents when implemented by community‐based organizations: a cluster‐randomized controlled trial. American Journal of Public Health 2010;100(4):720‐26.

Kirby 1997a {published data only}

Kirby D, Korpi M, Adivi M, Weissman J. An impact evaluation of project SNAPP: an AIDS and pregnancy prevention middle school program. AIDS Education and Prevention 1997;9(suppl 1):44‐61.

Kirby 1997b {published data only}

Kirby D, Korpi M, Barth RP, Cagampang HH. The impact of the postponing sexual involvement curriculum among youths in California. Family planning perspectives 1997;29:100‐8.

Kirby 2004 {published data only}

Kirby DB, Baumler E, Coyle KK, Basen‐Engquist K, Parcel GS, Harrist R, et al. The "Safer Choices" Intervention: Its Impact on the Sexual Behaviours of Different Subgroups of High School Students. Journal of Adolescent Health 2004;35:442‐52.

Kogan 2012 {published data only}

Kogan SM, Yu T, Brody GH, Chen Y, DiClemente RJ, Wingood GM, et al. Integrating condom skills into family‐centered prevention: efficacy of the Strong African American Families – teen program. Journal of Adolescent Health 2012;51(2):164‐70.

Markham 2012 {published data only}

Markham CM, Tortolero SR, Peskin MF, Shegog R, Thiel M, Baumler ER, et al. Sexual risk avoidance and sexual risk reduction interventions for middle school youth: a randomized controlled trial. Journal of Adolescent Health 2012;50:279–88.

Mba 2007 {published data only}

Mba CI, Obi SN, Ozumba BC. The impact of health education on reproductive health knowledge among adolescents in a rural Nigerian community. Journal of Obstetrics and Gynaecology 2007;27(5):513‐17.

Minnis 2014 {published data only}

Minnis AM, vanDommelen‐Gonzalez E, Luecke E, Dow W, Bautista‐Arredondo S, Padian NS. Yo puedo ‐ a conditional cash transfer and life skills intervention to promote adolescent sexual health: results of a randomized feasibility study in San Francisco. Journal of Adolescent Health 2014;55(1):85‐92.

Mitchell‐DiCenso 1997 {published data only}

Mitchell‐DiCenso A, Thomas BH, Devlin MC, Goldsmith CH, Willan A, Singer J, et al. Evaluation of an education program to prevent adolescent pregnancy. Health Education and Behaviour 1997;24(3):300‐12.

Morberg 1998 {published data only}

Morberg DP, Piper DL. The health for life project: sexual risk behaviour outcomes. AIDS Education and Prevention 1998;10(2):128‐48.

Morrison‐Beedy 2013 {published data only}

Morrison‐Beedy D, Jones SH, Xia Y, Tu X, Crean HF, Carey MP. Reducing sexual risk behavior in adolescent girls: results from a randomized controlled trial. Journal of Adolescent Health 2013;52(3):314‐21.

Norton 2012 {published data only}

Norton WE, Jeffrey D. Fisher JD, Rivet Amico K, Dovidio JF, Johnson BT. Relative efficacy of a pregnancy, sexually transmitted infection, or human immunodeficiency virus prevention–focused intervention on changing sexual risk behavior among young adults. Journal of American College Health 2012;60(8):574‐82.

O'Donnell 1999 {published data only}

O'Donnell L, Stueve A, Doval AS, Duran R, Haber D, Atnafou R, et al. The Effectiveness of the Reach for Health Community Youth Service Learning Program in Reducing Early and Unprotected Sex Among Urban Middle School Students. American Journal of Public Health 1999;89(2):176‐81.

O'Donnell 2002 {published data only}

O'Donnell L, Stueve A, O'Donnell C, Duran R, Doval AS, Wilson RF, et al. Long‐term reductions in sexual initiation and sexual activity among urban middle schoolers in the reach for Health Service learning program. Journal of Adolescent Health 2002;31:93‐100.

Okonofua 2003 {published data only}

Okonofua FE, Coplan P, Collins S, Oronsaye F, Ogunsakin D, Ogonor JT, et al. Impact of an intervention to improve treatment‐seeking behaviour and prevent sexually transmitted diseases among Nigerian youths. International Journal of Infectious Diseases 2003;7:61‐73.

Perskin 2015 {published data only}

Peskin MF, Shegog R, Markham CM, Thiel M, Baumler ER, Addy RC, et al. Efficacy of It's your Game‐Tech: a computer‐based sexual health education program for middle school youth. Journal of Adolescent Health 2015;56:515‐21.

Philliber 2002 {published data only}

Philliber S, Kaye JW, Herlings S, West E. Preventing pregnancy and improving health care access among teenagers: an evaluation of the children's aid society‐Carrera program. Perspectives on sexual and reproductive health 2002;34(5):244‐51.

Raine 2005 {published data only}

Raine TR, Harper CC, Rocca CH, Fisher R, Padian N, Klausner JD, et al. Direct access to emergency contraception through pharmacies and effect on unintended pregnancy and STIs. JAMA 2005;293:54‐62.

Raymond 2006 {published data only}

Raymond EG, Stewart F, Weaver M, Monteith C, Van Der Pol B. Impact of increased access to emergency contraceptive pills. Obstetrics and Gynecology 2006;108(5):1098‐106.

Shrier 2001 {published data only}

Shrier LA, Ancheta R, Goodman E, Chiou VM, Lyden MR, Emans SJ. Randomized controlled trial of a safer sex intervention for high‐risk adolescent girls. Archives of Pediatrics and Adolescent Medicine 2001;155:73‐9.

Sieving 2011 {published and unpublished data}

Sieving RE, McMorris BJ, Beckman KJ, Pettingell SL, Secor‐Turner M, Kugler K, et al. Prime Time: 12‐month sexual health outcomes of a clinic‐based intervention to prevent pregnancy risk behaviors. Journal of Adolescent Health 2011;49(2):172‐9.
Sieving RE, McRee A, McMorris BJ, Beckman KJ, Pettingell SL, Bearinger LH, et al. Sexual Health Outcomes at 24 months for a Clinic‐Linked Intervention to Prevent Pregnancy Risk Behaviors. JAMA Pediatric 2013;167(4):333‐340.

Smith 1994 {published data only}

Smith MAB. Teen incentives program: evaluation of a health promotion model for adolescent pregnancy prevention. Journal of Health Education 1994;25(1):24‐9.

Stephenson 2004 {published data only}

Stephenson JM, Strange V, Allen E, Copas A, Johnson A, Bonell C, et al. The long‐term effects of a peer‐led sex education programme (RIPPLE): a cluster randomised trial in schools in England. PLoS Medicine 2008;5(11):e224.
Stephenson JM, Strange V, Oakley A, Copas A, Allen E, Babiker. Pupil‐led sex education in England (RIPPLE study): cluster randomised intervention trial. Lancet 2004;364:338‐46.

Villarruel 2006 {published data only}

Villarruel AM, Jemmott JB, Jemmott LS. A randomized controlled trial testing an HIV prevention intervention for Latino youth. Arch Pediatr Adolesc Med 2006;160:772‐7.

Walker 2006 {published data only}

Walker D, Gutierrez JP, Torres P, Bertozzi SM. HIV prevention in Mexico schools; prospective randomized evaluation of intervention. BMJ 2006;332:1189‐94.

Wight 2002 {published data only}

Wight D, Raab GM, Henderson M, Abraham C, Buston K, Hart G, et al. Limits of teacher delivered sex education: interim behavioural outcomes from randomized trial. BMJ 2002;324:1430‐6.

References to studies excluded from this review

Agha 2002 {published data only}

Agha S. An evaluation of the effectiveness of a peer sexual health intervention among secondary‐school students in Zambia. AIDS 2002;14(4):269‐81.

Amin 2004 {published data only}

Amin R, Sato T. Impact of a school‐based comprehensive program for pregnant teens on their contraceptive use, future contraceptive intention, and desire for more children. Journal of Community Health Nursing 2004;21(1):39‐47.

Antunes 2002 {published data only}

Antunes MC, Peres CA, Paiva V, Stall R, Hearst N. Differences in AIDS prevention among young men and women of public schools in Brazil. Revista de Saúde Pública 2002;36(4 suppl):88‐95.

Barlow 2006 {published data only}

Barlow A, Varipatis‐Baker E, Speakman K, Ginsburg G, Friberg I, Goklish N, et al. Home‐visiting intervention to improve child care among American Indian adolescent mothers. Archives of Pediatrics and Adolescent Medicine 2006;160:1101‐7.

Barnet 2009 {published data only}

Barnet B, Liu J, DeVoe M, Duggan AK, Gold MA, Pecukonis E. Motivational intervention to reduce rapid subsequent births to adolescent mothers: a community‐based randomized trial. Annals of Family Medicine 2009;7(5):436‐45.

Barnet 2010 {published data only}

Barnet B, Rapp T, DeVoe M, Mullins CD. Cost‐effectiveness of a motivational intervention to reduce rapid repeated childbearing in high‐risk adolescent mothers: a rebirth of economic and policy considerations. Archives of Pediatrics and Adolescent Medicine 2010;164(4):370‐6.

Bonell 2005 {published data only}

Bonell C, Allen E, Strange V, Copas A, Oakley A, Stephenson J, et al. The effect of dislike of school on risk of teenage pregnancy: testing of hypotheses using longitudinal data from a randomized trial of sex education. Journal of Epidemiology and Community Health 2005;59:223‐30.

Bouris 2010 {published data only}

Bouris A, Guilamo‐Ramos V, Jaccard J, McCoy W, Aranda D, Pickard A, et al. The feasibility of a clinic‐based parent intervention to prevent HIV, sexually transmitted infections, and unintended pregnancies among latino and African American adolescents. AIDS Patient Care STDS 2010;24(6):381‐7.

Boyer 2005 {published data only}

Boyer CB, Shafer M, Shaffer RA, Brodine SK, Pollack LM, Betsinger K, et al. Evaluation of a cognitive ‐ behavioural, group, randomized controlled intervention trial to prevent sexually transmitted infections and unintended pregnancies in young women. Preventive Medicine 2005;40:420‐31.

Brinkman 2010 {published data only}

Brinkman SA, Johnson SE, Lawrence D, Codde JP, Hart MB, Straton JAY, et al. Study protocol for the evaluation of an Infant Simulator based program delivered in schools: a pragmatic cluster randomised controlled trial. Trials 2010;11(1):100.

Brown 2011 {published data only}

Brown KE, Hurst KM, Arden MA. Improving adolescent contraceptive use: evaluation of a theory‐driven classroom‐based intervention. Psychology, Health & Medicine 2011;16(2):141‐55.

Buston 2007 {published data only}

Buston K, Williamson L, Hart G. Young women under 16 years with experience of sexual intercourse: who became pregnant?. Journal of Epidemiology and Community Health 2007;61:221‐5.

Cagampang 1997 {published data only}

Cagampang HH, Barth RP, Korpi M, Kirby D. Education now and babies later (ENABL): life history of a campaign to postpone sexual involvement. Family Planning Perspectives 1997;29:109‐14.

Chesney 2003 {published data only}

Chesney MA, Koblin BA, Barresi PJ, Husnik MJ, Celum CL, Colfax G, et al. An individually tailored intervention for HIV prevention: baseline data from the EXPLORe study. American Journal of Public Health 2003;93:933‐8.

Chung‐Park 2008 {published data only}

Chung‐Park MS. Evaluation of a pregnancy prevention programme using the Contraceptive Behavior Change model. Journal of Advanced Nursing 2008;61(1):81‐91.

Cowan 2008 {published data only}

Cowan FM, Pascoe SJS, Langhaug LF, Dirawo J, Chidiya S, Jaffar S, et al. The Regai Dzive Shiri Project: a cluster randomised controlled trial to determine the effectiveness of a multi‐component community‐based HIV prevention intervention for rural youth in Zimbabwe – study design and baseline results. Tropical Medicine and International Health 2008;13(10):1235‐44.

Crosby 2005 {published data only}

Crosby RA, DiClemente RJ, Wingwood GM, Salazar LF, Rose E, Levine D, et al. Condom failure among adolescents: Implications for STD prevention. Journal of Adolescent Health 2005;36:534‐6.

Danielson 1990 {published data only}

Danielson R, Marcy S, Plunkett A, Wiest W, Greenlick MR. Reproductive health counselling for young men: what does it do?. Family Planning Perspectives 1990;22(3):115‐22.

Decat 2014 {published data only}

Decat P, De Meyer S, Jaruseviciene L, Orozco M, Ibarra M, Segura Z, et al. Sexual onset and contraceptive use among adolescents from poor neighbourhoods in Managua, Nicaragua. The European Journal of Contraception and Reproductive Health Care 2014;20(2):1‐14.

Di 2004 {published data only}

Di Noia J, Schinke SP, Pena JB, Schwinn TM. Evaluation of a brief computer‐mediated intervention to reduce HIV risk among early adolescent females. Journal of Adolescent Health 2004;35(1):62‐4.

Diclemente 2001 {published data only}

Diclemente RJ, Wingwood GM, Crosby R, Cobb BK, Harrington K, Davies SL. Parent‐adolescent communication and sexual risk behaviours among African American adolescent females. The Journal of Pediatrics 2001;32(2):407‐12.

Doniger 2001 {published data only}

Doniger AS, Adams E, Utter CA, Riley JS. Impact evaluation of the "Not Me, Not Now" abstinence‐oriented, adolescent pregnancy prevention communications program, Monroe County, New York. Journal of Health Communications 2001;6:45‐60.

Dycus 1990 {published data only}

Dycus S, Costner G. Healthy early‐adolescent development (11‐13 years olds): Implementing a human sexuality. Elementary School Guidance & Counselling 1990;25(1):46‐54.

East 2003 {published data only}

East P, Kiernan E, Chavez G. An evaluation of California's adolescent sibling pregnancy prevention program. Perspectives on Sexual and Reproductive Health 2003;35(2):62‐70.

Eisen 1985 {published data only}

Eisen M, Zellman GL, McAlister AL. A health belief model approach to adolescents' fertility control: some pilot program findings. Health Education Quarterly 1985;12(2):185‐210.

Eisen 1987 {published data only}

Eisen M, Zellman GL. Changes in incidence of sexual intercourse of unmarried teenagers following a community‐based sex education program. The Journal of Sex Research 1987;23(4):527‐44.

El‐Bassel 2003 {published data only}

El‐Bassel N, Witte SS, Guilbert L, Wu E, Chang M, Hill J, et al. The efficacy of a relationship‐based HIV/STD prevention program for heterosexual couples. American Journal of Public Health 2003;93:963‐9.

Ferguson 1998 {published data only}

Ferguson SL. Peer counselling in a culturally specific adolescent pregnancy prevention program. Journal of Health Care for the Poor and Underserved 1998;9(3):323‐33.

Fitzgerald 2002 {published data only}

Fitzgerald SM, Jordan TR, Yoo LM, Hart R. Effectiveness of the responsible social values program for 6th grade students in one rural school district. Psychological Reports 2002;91:1129‐32.

Gallegos 2008 {published data only}

Gallegos EC, Villarruel AM, Loveland‐Cherry C, Ronis DL, Zhou Y. Intervention to reduce adolescents sexual risk behaviours: a randomized controlled trial. Salud Publica Mexico 2008;50:59‐66.

Garbers 2012 {published data only}

Garbers S, Meserve A, Kottke M, Hatcher R, Ventura A, Chiasson MA. Randomized controlled trial of a computer‐based module to improve contraceptive method choice. Contraception 2012;86(4):383‐90.

Gaughran 2014 {published data only}

Gaughran M, Asgary RJ. On‐site comprehensive curriculum to teach reproductive health to female adolescents in Kenya. Womens Health 2014;23(4):358‐64.

Guilamo‐Ramos 2011a {published data only}

Guilamo‐Ramos V, Jaccard J, Dittus P, Bouris A, Gonzalez B, Casillas E, et al. A comparative study of interventions for delaying the initiation of sexual intercourse among Latino and Black youth. Perspectives on Sexual and Reproductive Health 2011;43(4):247‐54.

Harvey 2004 {published data only}

Harvey SM, Henderson JT, Thorburn S, Casillas A, Mendez L, Cervantes R. A randomized study of a pregnancy and disease prevention intervention for Hispanic couples. Perspectives on Sexual and Reproductive Health 2004;36(4):162‐9.

Havens 1997 {published data only}

Havens KK, Wagstaff DA, Mercer PA, Longeway K, Gutman M. Lessons learned from a mentoring program for teenage mothers. Wisconsin Medical Journal 1997;96(9):38‐43.

Howard 1990 {published data only}

Howard M, McCabe JB. Helping teenagers postpone sexual involvement. Family Planning Perspectives 1990;22(1):21‐7.

Hutchinson 2003 {published data only}

Hutchinson MK, Jemmott JB, Jemmott LS, Braverman P, Fong GT. Role of a mother‐daughter sexual risk communication in reducing sexual risk behaviours among urban adolescent females: a prospective study. Journal of Adolescent Health 2003;33:98‐107.

James 2005 {published data only}

James S, Reddy PS, Ruiter RAC, Taylor M, Jinabhai CC, Van Empelen P, et al. The effects of a systematically developed photo‐novella on knowledge, attitudes, communication and behavioural intention with respect to sexually transmitted infections among secondary school learners in South Africa. Health Promotion International 2005;20(2):157‐65.

Jay 1984 {published data only}

Jay MS, DuRant RH, Shoffitt T, Linder CW, Litt IF. Effect of peer counselors on adolescent compliance in use of oral contraceptive. Pediatrics 1984;73(2):126‐31.

Jennings 2014 {published data only}

Jennings JM, Howard S, Perotte CL. Effects of a school‐based sexuality education program on peer educators: the Teen PEP model. Health Education Research 2014;29(2):319‐29.

Jewkes 2006 {published data only}

Jewkes R, Nduna M, Levin J, Jama N, Dunkle K, Khuzwayo N, et al. A cluster randomized controlled trial to determine the effectiveness of stepping stones in preventing HIV infections and promoting safer sex sexual behaviours amongst youth in the rural Eastern Cape, South Africa: trial design, methods and baseline findings. Tropical Medicine and International Health 2006;11(1):3‐16.

Kaljee 2005 {published data only}

Kaljee LM, Genberg B, Riel R, Cole M, Tho le H, Thoa le TK, et al. Effectiveness of a theory‐based risk reduction HIV prevention program for Vietnamese adolescents. AIDS education and prevention 2005;17(3):185‐99.

Kamali 2002 {published data only}

Kamali A, Kinsman J, Nalweyiso N, Mitchell K, Kanyesigye E, Kengeya‐Kayondo JF, et al. A community randomized controlled trial to investigate impact of improved STD management and behavioural interventions on HIV incidence in rural Masaka, Uganda: trial design, methods and baseline findings. Tropical Medicine and International Health 2002;7(12):1053‐63.

Katz 2011 {published data only}

Katz KS, Rodan M, Milligan R, Tan S, Courtney L, Gantz M, et al. Efficacy of a randomized cell phone‐based counseling intervention in postponing subsequent pregnancy among teen mothers. Maternal and Child Health Journal 2011;15 Suppl 1:S42‐53.

Kirby 2002a {published data only}

Kirby D. Effective approaches to reducing adolescent unprotected sex, pregnancy and childbearing. The Journal of Sex Research 2002;39(1):51‐7.

Kirby 2002c {published data only}

Kirby D. The impact of schools and school programs upon adolescent sexual behaviour. The Journal of Sex Research 2002;39(1):27‐33.

Kuroki 2008 {published data only}

Kuroki LM, Allsworth JE, Redding CA, Blume JD, Peipert JF. Is a previous unplanned pregnancy a risk factor for a subsequent unplanned pregnancy?. American Journal of Obstetrics and Gynecology 2008;199:517.e1‐517.e7.

Kyrychenko 2006 {published data only}

Kyrychenko P, Kohler C, Sathiakumar N. Evaluation of a school‐based HIV/AIDS educational intervention in Ukraine. Journal of Adolescent Health 2006;39:900‐7.

Legardy 2005 {published data only}

Legardy JK, Macaluso M, Artz L, Brill I. Do participants' characteristics influence the effectiveness of behavioural intervention? Promoting condom use of women. Sexually Transmitted Diseases 2005;32(1):665‐71.

Liberman 2000 {published data only}

Liberman LD, Gray H, Wier M, Fiorentino R, Maloney P. Long‐term outcomes of an abstinence‐based small‐group pregnancy prevention program in New York City schools. Family Planning Perspectives 2000;32(5):237‐45.

Magnani 2005 {published data only}

Magnani R, MacIntyre K, Karim AM, Brown L, Hutchinson P. The impact of life skills education on adolescent sexual risk behaviours in KwaZulu‐Natal, South Africa. Journal of Adolescent Health 2005;36:289‐304.

Martiniuk 2003 {published data only}

Martiniuk ALC, O'Connor KS, King WD. A cluster randomized trial of sex education programme in Belize, Central America. International Journal of Epidemiology 2003;32:131‐6.

Matteson 2006 {published data only}

Matteson KA, Peipert JF, Allsworth J, Phipps MG, Redding CA. Unplanned pregnancy. Does past experience influenced use of a contraceptive method?. Obstetrics & Gynecology 2006;107(1):121‐7.

McBride 2000 {published data only}

McBride D, Glenapp A. Using randomized designs to evaluate client‐centered programs to prevent adolescent pregnancy. Family Planning Perspectives 2000;32(5):227‐35.

Metcalf 2005 {published data only}

Metcalf CA, Malotte CK, Douglas JM, Paul SM, Dillon BA, Cross H, et al. Efficacy of a booster counselling session 6 months after HIV testing and counselling. A randomized controlled trial (RESPECT‐2). Sexually Transmitted Diseases 2005;32(2):123‐9.

Mitchell 2014 {published data only}

Mitchell EM, Heumann S, Araujo A, Adesse L, Halpern CT. Brazilian adolescents' knowledge and beliefs about abortion methods: a school‐based internet inquiry. BMC Women's Health 2014;14:27.

O'Donnell 2005 {published data only}

O'Donnell L, Stueve A, Agranick G, Wilson‐Simmons R, Duran R, Jeanbaptistie V. Saving sex for later: an evaluation of a parent education intervention. Perspectives on Sexual and Reproductive Health 2005;37(4):166‐73.

Ochiogu 2011 {published data only}

Ochiogu IN, Miettola J, Ilika AL, Vaskilampi T. Impact of timing of sex education on teenage pregnancy in Nigeria: cross‐sectional survey of secondary school students. Journal of Community Health 2011;36(3):375‐80.

Olsen 1991 {published data only}

Olsen JA, Weed SE. The effects of three abstinence sex education programs on student attitudes toward sexual activity. Adolescence 1991;26(103):631‐42.

Padian 2007 {published data only}

Padian NS, Van der Straten A, Ramjee G, Chipato T, de Bruyn G, Blanchard K, et al. Diaphragm and lubricant gel for prevention of HIV acquisition in Southern African women: a randomized controlled trial. Lancet 2007;370:251‐61.

Peipert 2008 {published data only}

Peipert JF, Redding CA, BLume JD, Allsworth JE, Matteson KA, Lozowski F, et al. Tailored intervention to increase dual‐contraceptive method use: a randomized trial to reduce unintended pregnancies and sexually transmitted infections. American Journal of Obstetrics and Gynecology 2008;198:630.e1‐630.e8.

Peipert 2011 {published data only}

Peipert JF, Zhao Q, Meints L, Peipert BJ, Redding CA, Allsworth JE. Adherence to dual‐method contraceptive use. Contraception 2011;84(3):252‐8.

Peipert 2012 {published data only}

Peipert JF, Madden T, Allsworth JE, Secura GM. Preventing unintended pregnancies by providing no‐cost contraception. Obstetrics & Gynecology 2012;120(6):1291‐7.

Peragallo 2005 {published data only}

Peragallo N, Deforge B, O'Campo P, Lee SM, Kim YJ, Cianelli R, et al. A randomized clinical trial of an HIV‐Risk reduction intervention among low income Latina women. Nursing research 2005;54(2):108‐18.

Peterson 2007 {published data only}

Peterson R, Albright J, Garrett JM, Curtis KM. Pregnancy and STD prevention counselling using an adaptation of motivational interviewing: a randomized controlled trial. Perspectives on Sexual and Reproductive Health 2007;39(1):21‐8.

Proude 2004 {published data only}

Proude EM, D'Este C, Ward JE. Randomized trial in family practice of a brief intervention to reduce STI risk in young adults. Family Practice 2004;21(5):537‐44.

Rickert 2007 {published data only}

Rickert VI, TIezzi L, Lipshutz J, Leon J, Vaughan RD, Westhoff C. Depo Now: preventing unintended pregnancies among adolescent and young adults. Journal of Adolescent Health 2007;40:22‐8.

Robin 2004 {published data only}

Robin L, Dittus P, Whitaker D, Crosby R, Ethier K, Mezoff J, et al. Behavioural interventions to reduce incidence of HIV, STD and pregnancy among adolescents: a decade in review. Journal of Adolescent Health 2004;34:3‐26.

Schreiber 2010 {published data only}

Schreiber CA, Ratcliffe SJ, Barnhart KT. A randomized controlled trial of the effect of advanced supply of emergency contraception in postpartum teens: a feasibility study. Contraception 2010;81(5):435‐40.

Schwarz 2008 {published data only}

Schwarz EB, Gerbert B, Gonzales R. Computer‐assisted provision of emergency contraception a randomized controlled trial. Journal of General and Internal Medicine 2008;23(6):794‐9.

Secura 2014 {published data only}

Secura GM. Adams T, Buckel CM, Zhao QH, Peipert JF. Change in sexual behavior with provision of no‐cost contraception. Obstetrics and Gynecology 2014;123(4):771‐6.

Shuey 1999 {published data only}

Shuey DA, Babishangire BB, Ominat S, Bagarukayo H. Increased sexual abstinence among in‐school adolescents as a result of school health education in Soroti district, Uganda. Health Education Research 1999;14(3):411‐9.

Sieving 2012 {published data only}

Sieving RE, Bernat DH, Resnick MD, Oliphant J, Pettingell S, Plowman S, et al. A clinic‐based youth development program to reduce sexual risk behaviors among adolescent girls: prime time pilot study. Health Promotion Practice 2012;13(4):462‐71.

Silva 2002 {published data only}

Silva M. The effectiveness of school‐based sex education programs in the promotion of abstinent behaviour: a meta‐analysis. Health Education Research 2002;17(4):471‐81.

Stout 1989 {published data only}

Stout JW, Rivara FP. Schools and sex education: does it work?. Pediatrics 1989;83(3):375‐9.

Thato 2008 {published data only}

Thato 2008, Jenkins RA, Dusitsin N. Effects of the culturally‐sensitive comprehensive sex education programme among Thai secondary school students. Journal of Advanced Nursing 2008;62(4):457‐69.

Thomas 2000 {published data only}

Thomas MH. Abstinence‐based programs for prevention of adolescent pregnancies. Journal of Adolescent Health 2000;26:5‐17.

Thomas 2004 {published data only}

Thomas DV, Looney SW. Effectiveness of a comprehensive psychoeducation intervention with pregnant and parenting adolescents: a pilot study. Journal of Child and Adolescent Psychiatric Nursing 2004;17(2):66‐77.

Tingle 2002 {published data only}

Tingle LR. Evaluation of the North Carolina "Baby Think it Over" Project. (Research Paper). Journal of School Health 2002;75(5):178(6).

Van 1985 {published data only}

Van D, Leslie J. Use of nurse‐client contracting to reduce risk of unintended pregnancy in an adolescent population. The American Public Health Association Annual Meeting1985.

Van Devanter 2002 {published data only}

Van Devanter N, Gonzales V, Merzel C, Parikh NS, Celantano D, Greenberg J. Effect of an STD/HIV behavioural intervention on women's use of the female condom. American Journal of Public Health 2002;92:109‐15.

Wiggins 2009 {published data only}

Wiggins M, Bonell C, Sawtell M, Austerberry H, Burchett H, Allen E, et al. Health outcomes of youth development programme in England: prospective matched comparison study. BMJ 2009;339:b2534.

Yoo 2004 {published data only}

Yoo S, Johnson CC, Rice J, Manuel P. A qualitative evaluation of the Students of Service (SOS) program for sexual abstinence in Louisiana. Journal of School Health 2004;74(8):329‐34.

Zabin 1986 {published data only}

Zabin LS, Hirsch MB, Smith EA, Streett R, Hardy JB. Evaluation of a pregnancy prevention program for urban teenagers. Family Planning Perspectives 1986;183(3):119‐26.

Zabin 1988 {published data only}

Zabin LS, Hirsch MB, Smith EA, Smith M, Emerson MR, King TM, et al. The Baltimore pregnancy prevention program for urban teenagers: II. what did it cost?. Family Planning Perspectives 1988;20(4):188‐92.

Zimmerman 2008 {published data only}

Zimmerman RS, Cupp PK, Donohew L, Sionean CK, Feist‐Price S, Helme D. Effects of a school‐based, theory‐driven HIV and Pregnancy prevention curriculum . Perspectives on Sexual and Reproductive Health 2008;40(1):42‐51.

References to studies awaiting assessment

Murray 2015 {published data only}

Murray PJ, Ashcraft AM, Downs J. Can you get an STI from a virgin? The answer might surprise you: Intervention improves knowledge about sexual risk perception. Journal of Pediatric Adolescent Gynecology (Poster Abstracts)2015; Vol. 28:e41‐e78.

Shafii 2014 {published data only}

Shafii T, Benson SK, Morrison DM, Hughes JP, Golden MR, Holmes KK. Results from ekiss (electronic kiosk intervention for safer‐sex): A pilot randomized controlled trial to test an interactive computer‐based intervention for sexual health in adolescents and young adults. Journal of Adolescent Health 2014;54(2 Suppl. 1):S10.

Adam 2004

Adams G, Gulliford MC, Ukoumunne OC, Eldridge S, Chinn S, Campbell MJ. Patterns of intra‐cluster correlation from primary care research to inform study design and analysis. Journal of Clinical Epidemiology 2004;57:785‐94.

Antman 1992

Antman EM, Lau J, Kupelnick B, Mostellar F, Chalmers TC. A comparison of results of meta‐analyses of randomized control trials and recommendations of clinical experts. Journal of the American Medical Association 1992;268:240‐8.

Burt 1986

Burt MR. Estimating the public cost of teenage childbearing. Family Planning Perspective 1986;18:221‐6.

Burt 1990

Burt MR. Public cost and policy implications of teenage childbearing. Adv Adolescent Mental Health 1990;4:265‐80.

Clark 2004

Clark M, Oxman MD. Cochrane Reviewers' Handbook. The Cochrane Library [database on disk and CDROM]. Oxford, 2004, issue 3.

Cook 1993

Cook DJ, Guyatt GH, Ryan G, Clifton J, Buckingham L, Willan A, et al. Should unpublished data be included in meta‐analyses? Current convictions and controversies. JAMA 1993;269:2749‐53.

Coyle 2001

Coyle KK, Basen‐Enquist KM, Kirby DB, Parcel GS, Banspach SW, Collins JL, et al. Safer choices: reducing teen pregnancy, HIV and STDs. Public Health Reports 2001;1(16):82‐93.

Deeks 2011

Deeks JJ, Higgins JPT, Altman DG (editors). Chapter 9: Analysing data and undertaking meta‐analyses. In: Higgins JPT, Green S (editors).Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

DeLamater 2000

Delamater J, Wagstaff DA, Havens KK. The impact of a culturally appropriate STD/AIDS education intervention on black male adolescents' sexual and condom use behaviour. Health Education and Behaviour 2000;27(4):453‐69.

Denny 2006

Denny G, Young M. An evaluation of an abstinence‐only sex education curriculum: an 18‐months follow‐up. Journal of School Health 2006;76(8):414‐22.

DiCenso 2002

DiCenso A, Guyatt G, Willan A, Griffith L. Interventions to reduce unintended pregnancies among adolescents: systematic review of randomized controlled trials. BMJ 2002;342:1‐9.

Dickersin 1990

Dickersin K. The existence of publication bias and risk factors for its occurrence. JAMA 1990;263:1385‐9.

Elfebein 2003

Elfebein DS, Felice ME. Adolescent pregnancy. Pediatric Clinics of North America 2003;50(4):781‐800.

Finer 2006

Finer LB, Zolna MR. Unintended pregnancy in the United States: incidence and disparities. Contraception 2006;84(5):478–85.

Franklin 1997

Franklin C, Grant D, Corcoran J, Miller P, Bultman L. Effectiveness of prevention programs for adolescent pregnancy: a meta‐analysis. Journal of Marriage and Family 1997;59:551‐67.

Fullerton 1997

Fullerton D, Dickson R, Eastwood AJ, Sheldon TA. Preventing unintended teenage pregnancies and reducing their adverse effects. Quality in Health Care 1997;6(2):102‐8.

Grossman 1992 [Computer program]

Grossman JB, Sipe CL. Summer training and Education Program (STEP): Report on long‐term impacts. Philadelphia: Public/Private Ventures, 1992.

Hamilton 2014

Hamilton BE, Martin JA, Osterman MJK, Curtin SC. Birth: Preliminary Data for 2013 National Vital Statistics Reports. Vol. 63, Hyattsville, Maryland: National Center for Health Statistics., May 29, 2014.

Haveman 1997

Haveman RH, Wolfe B, Peterson E. Children of early childbearers as young adults. In: In R.A. Maynard editor(s). Kids having kids: economic costs and social consequences of teen pregnancy. New York: The Robin Hood Foundation, 1997.

Helmerhorst 2004

Helmerhorst F, Helmerhorst A. Cochrane Fertility Regulation Group. In: The Cochrane Library, Issue 3, 2004. Chichester, UK: John Wiley & Sons, Ltd.

Henshaw 2000

Henshaw SK, Feivelson DJ. Teenage abortion and pregnancy statistics by state. Family Planning Perspectives 2000;32(6):272‐80.

Higgins 2011a

Higgins JPT, Altman DG, Sterne JAC (editors). Chapter 8: Assessing risk of bias in included studies. In: Higgins JPT, Green S (editors).Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Higgins 2011b

Higgins JPT, Deeks JJ, Altman DG (editors). Chapter 16: Special topics in statistics. In: Higgins JPT, Green S (editors), Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Higgins 2011c

Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011.. Available from www.cochrane‐handbook.org.

Hollis, 1999

Hollis S, Campbell F. What is meant by intention‐to‐treat analysis?. BMJ 1999;319:670‐74.

Kirby 2002b

Kirby D. Antecedents of adolescent initiation of sex, contraceptive use, and pregnancy. American Journal of Health Behavior 2002;26(6):473‐85.

Klerman 2002

Klerman LV. Adolescent pregnancy in the United States. International Journal of Adolescent Medical Health 2002;14(2):91‐6.

Koniak‐Griffin 2001

Koniak‐Griffin D, Turner‐Pluta C. Health risks and psychosocial outcomes of early childbearing: a review of the literature. Journal of Perinatal and Neonatal Nursing 2001;15(2):1‐17.

Kosunen 2002

Kosunen EA, Vikat A, Gissler M, Rimpela. Teenage pregnancies and abortions in Finland in the 1990s. Scandinavian Journal of Public Health 2002;30(4):300‐5.

Lindberg 2006

Lindberg LD, Frost JJ, Sten C, Dailard C. Provision of contraceptive and related services by publicly funded family planning clinics. Perspectives on Sexual and Reproductive Health 2006;38(3):139‐47.

Maness 2013

Maness SB, Buhi ER. A systematic review of pregnancy prevention programs for minority youth in the US: a critical analysis and recommendations for improvement. Journal of Health Disparities Research and Practice 2013;6(2):91‐106.

Manlove 2002

Manlove J, Terry‐Humen E, Papillo RA, Franzentta K, Williams S, Ryan S. Preventing teenage pregnancy, childbearing and STDs [What the Research Shows]. Child Trends Research Brief2002.

Maynard 1996

Maynard RA. Kids having kids: A Robin Hood Foundation special report on the costs of adolescent childbearing. New York: Robin Hood Foundation, 1996.

Mehra 2004

Mehra S, Agrawal D. Adolescent health determinants for pregnancy and child health outcomes among the urban poor. Indian Journal of Pediatrics 2004;41(2):137‐45.

Monea 2011

Monea E, Thomas A. The high cost of unintended pregnancy. CCF Briefs #45July 2011.

Moore 1993

Moore KA, Myers DE, Morrison DR, Winquist Nord C, Brown B, Edmonston B. Age at first childbirth and later poverty. Journal of Research on Adolescence 1993;3:393‐422.

Nelson 1990

Nelson PB. Repeat pregnancy among adolescent mothers: a review of the literature. Journal of the National Black Nurses Association 1990;4(1):28‐34.

NRC 1987

National Research Council. Risking the future: adolescent sexuality, pregnancy, and childbearing. Cheryl D. Hayes. Washington DC: National Academy Press, 1987.

O'Donnell 2003 [Computer program]

O'Donnell L, Doval A.S, Duran R, Haber D, Atnafou R, Piessens P, et al. Reach for health: a school sponsored community youth service intervention for middle school students.. Los Altos, CA:Sociometrics, 2003.

Orr 1996

Orr DP, Langefeid CD, Katz BP, Caine VA. Behavioural intervention to increase condom use among high‐risk female adolescents. Journal of Pediatrics 1996;128(2):288‐95.

Oxman 1993

Oxman AD, Guyatt GH. The science of reviewing research. Annals of the New York Academy of Science 1993;703:125‐33.

Pettinato 2003

Pettinato A, Emans SJ. New contraceptive methods: update 2003. Current Opinion in Pediatrics 2003;15(4):362‐9.

Philliber 1992

Philliber S, Allen JP. Life options and community service: teen outreach program [Miller BC, Card JJ, Paikoff RL and Peteson JL (Eds)]. Prevention adolescent pregnancy. Newburg Park, CA: Sage Publications, 1992:139‐155.

Phipps 2002

Phipps MG, Blume JD, DeMonner SM. Young maternal age associated with increased risk of post‐neonatal death. Obstetrics and Gynecology 2002;100(3):481‐6.

Raine 2000

Raine T, Harper C, Leon K, Darney P. Emergency contraception: advance provision in a young, high‐risk clinic population. Obstetrics and Gynecology 2000;96(1):1‐7.

Rao 1992

Rao JN, Scott AJ. A simple method for analysis of clustered binary data. Biometrics 1992;48(2):577‐85.

RevMan 2014 [Computer program]

The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.

Rich‐Edwards 2002

Rich‐Edwards J. Teen pregnancy is not a public health crisis in the United States: it is time we made it one. International Journal of Epidemiology 2002;31:555‐6.

Schünemann 2011

Schünemann HJ, Oxman AD, Vist GE, Higgins JPT, Deeks JJ, Glasziou P, et al. Chapter 12: Interpreting results and drawing conclusions. In: Higgins JPT, Green S (editors), Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Sikron 2003

Sikron F, Wilf‐Miron R, Israeli A. Adolescent pregnancy in Israel: methodology for rate estimation and analysis of characteristics and trends. Harefuah 2003;142(2):131‐6.

St. Lawrence 2005

St. Lawrence JS. Becoming a responsible teen: an HIV risk‐reduction program for adolescents. Scott valley, CA: ETR Associates2005.

Sterne 2011

Sterne JAC, Egger M, Moher D (editors). Chapter 10: Addressing reporting biases. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Thomas 2009

Thomas A, Monea E. FamilyScape: a simulation model of family formation. The Brookings Institution, Washington, D.C.2009.

Thomas 2012

Thomas A. Policy solutions for preventing unplanned pregnancy. Center on Children and Families at Brookings (CCF) BriefsMarch 2012.

Trussell 1997

Trussell J, Koenig J, Stewart F, Darroch JE. Medical care cost savings from adolescent contraceptive use. Family Planning Perspectives 1997;29(6):248‐55, 295.

Upchurch 1990

Upchurch DM, McCarthy JL. The timing of first birth and high school completion. American Sociological Review 1990;55:224‐34.

WHO 1980

World Health Organization. Regional Working Group on health needs of adolescents: final report. WHO Document ICP/MCH/005. Manila: World Organization, Regional Office for the Western Pacific, 1980.

WHO 1995

World Health Organization. World Health Report, 1995 ‐ Closing the gap. Geneva: World Health Organization, 1995.

World Bank 2014

The World Bank. Adolescent fertility rate (births per 1000 women ages 15‐19). United Nations Population Division, World Population Prospects. The 2010 Revision2011.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Aarons 2000

Methods

Cluster‐randomis ed controlled study; method of generating allocation sequence not mentioned in the paper
Unit of randomis ation: schools

Participants

582 students who enrolled in the 7th grade at the beginning of the study; enrolled in the 8th grade at the beginning of the 1996/1997 session; capable of reading and comprehending the questionnaire in English or Spanish; not truant or suspended during the trial; mean age of 12.8 years; 52% female and 48% male; 84% African American, 13% Hispanic, 2% other, low socio‐economic status

Interventions

Intervention: t hree 45‐ minute reproductive health education classes by health professionals, five 45‐ minute sessions on postponing sexual involvement by peer leaders in 10th and 11th grades, health risk assessment questionnaire

Control: conventional education programme

Outcomes

Initiation of intercourse (age at initiation), use of birth control/condoms at last sex

Notes

Duration of follow up: 15 months.

Loss to follow up: 19%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method used for allocation sequence generation not provided

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Intention‐to‐treat analysis

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Unclear risk

Did not control for cluster randomi sation during the analysis

Allen 1997

Methods

Randomis ed controlled trial. Randomis ation was done at two levels; student (75% of sample) by picking names out of a hat or choosing every other name on an alphabetis ed list, and classroom (25% of sample) by a coin toss

Participants

695 students from 25 sites in the United States, 9th grade to 12th grade, mean age of 15.8 years, 85% female and 15% male; 67% African American, 19% White, 11% Hispanic and 3% other

Interventions

Intervention: 20 hours per year of supervised community volunteer services and one hour per week of classroom‐ based discussion of service experiences, future life options, developmental tasks of adolescents and sex education

Control: standard curriculum offerings

Outcomes

Unintended pregnancy (women only)

Notes

Duration of follow up: nine months

Loss to follow up: 7.0% lost to follow up (5.3% among experimental students and 8.4% among control students)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Picking names out of a hat (for individual) or coin toss (for classrooms)

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

No information provided on this domain

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Three sites were excluded from analysis. Higher attrition rate in the control groups. There were some differences between students lost and those retained in that students lost were more likely to have had or caused a prior pregnancy, been suspended, be younger and be male.

Selective reporting (reporting bias)

Low risk

Pre‐specifed outcomes were reported

Other bias

Low risk

The study appears to be free from other bias

Baird 2010

Methods

Cluster ‐ randomis ed controlled trial; randomis ation was done using Enumeration Areas (EAs).

Participants

Young women aged 12 years to 22 years and not married

Interventions

Intervention: conditional cash transfer (CCT) as an incentive for school girls and young women to stay or return to school

Control: no CCT provided

Outcomes

Pregnancy, sexual behaviour (onset of sexual activity, number of sexual partners in the past 12 months, condom use, frequency of sexual activity)

Notes

Duration of follow up: 12 months

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Information on this domain was not provided

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Attrition rate was low and balanced across treatment and control groups

Selective reporting (reporting bias)

Unclear risk

Outcomes to be measured were not clearly listed in the methods

Other bias

Unclear risk

Baseline differences between dropouts and school girls (dropouts were older, less literate and more likely to have started childbearing)

Basen‐Engquist 2001

Methods

Cluster‐randomis ed controlled study. Method of generating allocation sequence not mentioned in the paper

Unit of randomis ation: schools

Participants

7614, 8319 and 9489 9 (at baseline, 19 and 31 months); grade 9 to 12 students in schools in California and Texas, 47% male, 53% female, 18% African American, 17% Asian, 33% Hispanic, 27% White, 5% other

Interventions

Intervention: 20 sessions of health education, skills‐ building, contraceptive education, social norms and peer education, parent education, community linkages

Control: standard knowledge‐ based curriculum on contraception, HIV and other STDs

Outcomes

Initiation of intercourse, contraception use

Notes

Duration of follow up: 31 months

Loss to follow up: not clear

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Insufficient information on attrition/exclusion to permit judgement as number of participants in the study increased with each follow up.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Unclear risk

The sampling methods for including students not clear

Black 2006

Methods

Randomis ed controlled study. Method of allocation sequence not mentioned. Unit of randomis ation: individual

Participants

181 adolescent mothers in urban hospitals who were living with their mother, 13.5 years to 17.9 years at delivery, first‐time delivery, Black, no history of drugs, infants should be 37 weeks and birth weight of > 2500 g with no congenital problems, chronic illnesses, or disabilities.

Interventions

Intervention: home mentoring programme (home visits every week until infant's first birthday, approximately 19 visits)

Control: no intervention

Outcomes

Second unintended pregnancy

Notes

Duration of follow up: 24 months

Loss to follow up: 18%

Evaluators were blinded to intervention status

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Evaluators only

Incomplete outcome data (attrition bias)
All outcomes

High risk

Only participants with both baseline and 24‐months' data were included in the analysis.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other bias

Blake 2001

Methods

Cluster‐randomis ed controlled study. Quarterly marking period within schools was used to generate allocation sequence

Unit of randomis ation: schools

Participants

351 8th grade students in Rochester, New York living in middle class suburban communities, 48% female and 52% male. 85% were white and non‐Hispanic.

Interventions

Intervention: enhanced intervention; five one‐hour sessions on standard school‐ based curriculum ( health education; skills‐ building; abstinence; communication skills) plus five parent‐child homework assignments on sexuality and sexual behaviour led by trained youth leaders

Control: standard school‐ based curriculum only

Outcomes

Initiation of intercourse, knowledge on the risk of pregnancy

Notes

Duration of follow up: seven weeks. No mention of loss to follow up

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Quarterly marking period within schools

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Only those who completed pre‐test and post‐test questionnaires were analys ed at baseline and end of the study. Analysis adjusted for clusters

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes were reported

Other bias

High risk

Selection bias as the proportion of students who had completed no assignments was higher among Black and Hi spanic adolescents than among non‐Hispanic White students (43% vs 18%; P < 0.05); higher among male than female students (27% vs 9%; P < 0.01) and was higher among adolescents who reported recent sexual intercourse than among those who did not (63% vs 17%; P < 0.001)

Bonell 2013

Methods

Matched‐pair individual‐allocation randomi sed trial.

Participants

Girls aged 13 years to 15 years

Interventions

Intervention: weekly three‐hour sessions in pre‐school nuseries to develop awareness of the responsibility involved in parenting, self‐awareness and confidence to reduce risk of teenage pregnancy, other issues addressed include self‐esteem and sense of control, emotional literacy and social skills, teenage sex, sexual health and consequences of unplanned pregnancy

Control: not stated

Outcomes

Last sex without contraception in the last three months, more than one episode of sex without contraception in the last three months, new pregnancy since baseline, last sex without condom in the last three months, more than one episode of sex without condom in the last three months

Notes

Duration of follow up: 22 weeks and 12 months

Loss to follow up; 9%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated random number

Allocation concealment (selection bias)

Unclear risk

Children: Our Ultimate Investment (COUI) and school staff were blinded to allocation; however, neither intervention teachers, nor girls nor analyst were blinded to allocation status

Blinding (performance bias and detection bias)
All outcomes

High risk

Teachers and girls were not blinded to allocation status

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Few number of participants lost to follow up; intention‐ to‐ treat analysis was employed

Selective reporting (reporting bias)

High risk

Pregnancy was based on self‐reporting

Other bias

Unclear risk

The study appears to be free from other bias

Borgia 2005

Methods

Cluster‐randomis ed controlled study. Method of allocation concealment not mentioned.

Unit of randomization: schools

Participants

1295 students from 18 high schools in Rome, 51% male, 49% female, mean age 18.3 years

Interventions

Intervention: HIV/AIDS education and skills‐ building by peer

Control: same intervention by teachers

Outcomes

Consistent condom use

Notes

Duration of follow up: 5 months

Loss to follow up: 20% for peer‐led group and 27% teacher‐led group

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Trial authors stated they used an intention‐to‐treat analysis, whereby classes which did not perform the interventions were included in the outcome evaluation. Analysis adjusted for clusters

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Cabezon 2005

Methods

Cluster‐randomis ed controlled trial. Classrooms were randomised by blindly, taking letters of the class from a bag (simple balloting)

Unit of randomis ation: classrooms

Participants

1259 9th grade female students in San Bernardo, Chile, aged 15 years to 16 years, White Hispanic, who had initiated high school in 1997 and 1998.

Interventions

Intervention: one 45‐ minute class per week for a year on health education, contraceptive education, skills‐ building and abstinence

Control: no intervention

Outcomes

Unintended pregnancy

Notes

Duration of follow up: 4 years

Loss to follow up: 19%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Simple balloting (blindly taking letters from a bag)

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Per‐ protocol analysis was carried out but missing outcome data balanced in numbers across intervention groups with similar reasons for missing data across groups (change of residence and financial problems)

Selective reporting (reporting bias)

Low risk

Stated outcomes were measured

Other bias

Low risk

The study appears to be free from other bias

Clark 2005

Methods

Cluster‐randomis ed controlled study. Method of allocation sequence not mentioned

Unit of randomis ation: class

Participants

211 African American 7th grade students, 11 years to 14 years of age, 55% male, 45% female, low income

Interventions

Intervention: 10 sessions (once or twice per week for six weeks) on skills‐ building and career mentoring

Control: standard health curriculum

Outcomes

Initiation of intercourse

Notes

Duration of follow up: 1 year

Loss to follow up: 26%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Only participant, the provided baseline, and end of study information were included in the one‐ year follow‐ up analysis

Selective reporting (reporting bias)

Low risk

Stated outcome reported

Other bias

Unclear risk

The study appears to be free from other sources of bias

Coyle 1999

Methods

Cluster‐randomis ed controlled study. Method of allocation sequence not mentioned in this study

Unit of randomis ation: schools

Participants

3869 9th grade students from 20 urban high schools in Texas and California, mean age 15 years, 53% female and 47% male; 31% White, 27% Hispanic, 18% Asian or Pacific Islanders, 16% African‐American, < 1% African Indian, 7% other

Interventions

Intervention: 20 sessions on health education, skills‐ building, contraceptive education, parent education, community linkages

Control: standard knowledge‐ based HIV‐ prevention curriculum

Outcomes

Initiation of intercourse, use of contraceptive at last sex

Notes

Duration of follow up: 7 months

Loss to follow up: 3%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not described

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Whereas only those with data at baseline and at follow up were included in the analysis, there were no differences in the sexual behaviours between those lost to follow up and those who remained in the study across groups.

Selective reporting (reporting bias)

Low risk

Stated outcomes reported

Other bias

Low risk

Appears to be free from other bias

Coyle 2004

Methods

Randomis ed controlled study. Method of generating allocation sequence not mentioned in the paper

Unit of randomis ation: schools

Participants

2829 6th grade students with an average age of 11.5 years from 19 schools in Northern California; 50% female and 50% male; 5.2% African American, 15.9% Asian, 59.3% Hispanic 16.5% White and 3.1% Other.

Interventions

Intervention: 20‐ session curriculum ( five lessons in 6th grade on skills‐ building in non‐sexual situations, eight lessons in 7th grade on determining personal limits in intercourse, understanding consequences of unplanned sexual intercourse (including pregnancy and STD), skills‐ building, seven lessons in 8th grade on contraception education, HIV‐infected speaker and refusal skills in dating)

Control: standard curriculum

Outcomes

Initiation of intercourse

Notes

Duration of follow up: 36 months; lost to follow up: 36%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

High risk

High attrition rate among participants

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Coyle 2006

Methods

Cluster‐randomi sed controlled study. Method of generation of allocation was done using restricted randomi sation into matched sets.

Unit of randomi sation: schools

Participants

988 students, 14 years to 18 years or older, in community day schools located in four urban counties in Northern California, 63% male, 37% female, 27% African American, 15% Asian American, 30% Hispanic, 12% White, 16% other

Interventions

Intervention: 14 sessions (26 hrs) on HIV/STDs/ pregnancy education, skills‐ building, risks related to sexual behaviour, contraception education and service learning activities ( five visits to volunteer sites)

Control: usual curriculum

Outcomes

Unintended pregnancy, initiation of intercourse, use of contraceptives and condoms at last sex

Notes

Duration of follow up: 18 months

Loss to follow up: 58%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Restricted randomis ation into matched set

Allocation concealment (selection bias)

Unclear risk

No information provided on this domain

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

All students were included in the analysis regardless of programme dose. No statistically significant difference was found in the rates of attrition across groups

Selective reporting (reporting bias)

Low risk

All expected/stated outcomes reported

Other bias

Low risk

The study seems to be free from other bias

Diclemente 2004

Methods

Randomis ed controlled study. Table of random numbers was used to generate allocation sequence. Unit of randomi sation: individual

Participants

522 female participants between the ages of 14 years to 18 years in four community health agencies in southern United States, African American, reporting vaginal intercourse in the preceding six months.

Interventions

Intervention: four‐hour interactive group sessions on ethnic and gender pride, health/HIV education, skills‐ building and contraception education

Control: four‐hour interactive group sessions on general health promotion condition (exercise and nutrition)

Outcomes

Unintended pregnancy, consistent condom use and sexually transmitted disease

Notes

Duration of follow up: 12 months. Loss to follow up: 12% (12.7% for intervention and 11.1% for the control). Assessors were blinded to participants' condition assignments. Allocation concealed in opaque envelopes

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Table of random numbers

Allocation concealment (selection bias)

Low risk

Use of sealed opaque envelopes

Blinding (performance bias and detection bias)
All outcomes

Low risk

Assessors were blinded

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Participants were analys ed in their groups irrespective of number of sessions attended. Missing outcome data balanced in numbers with similar reasons for missing data across groups

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Dilorio 2006

Methods

Randomis ed controlled study. Computer‐generated random numbers used to generate allocation sequence. Unit of randomi sation: sites

Participants

582 adolescents from a community‐ based organi sation and their mothers, 11 years to 14 years, 60% male, 40% female, 98% African American

Interventions

Intervention 1: seven sessions ( two hours) over 14 weeks ( four sessions for mother and adolescents together) on HIV education, communication skills, take‐ home activities and sexual decision making, consequences of early sexual intercourse

Intervention 2: stress reduction exercise and specific type of at‐risk behaviours including early sexual intercourse, take‐ home assignments and community service (mothers and adolescents attended the first and last sessions together)

Control: mothers and adolescents had a one‐hour HIV prevention session

Outcomes

Condom use at last sex among participants who have ever had sex

Notes

Duration of follow up: 24months.

Loss to follow up: 10%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer generated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Trial authors stated the use of intention‐ to‐ treat analysis; for the use of condoms, only respondents who indicated being sexually active were included in the analysis

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Dilorio 2007

Methods

Randomis ed controlled study. Method for generating allocation sequence not mentioned in the paper

Unit of randomi sation: sites

Participants

277 adolescent boys from seven sites in Atlanta, 11 years to 14 years, 96% African American

Interventions

Intervention: seven two‐hour sessions, 6th session for fathers of participants only, and the last session for both on communication, parental monitoring and relationship with peers, HIV/AIDS education

Control: seven sessions on nutrition and exercise

Outcomes

Ever had sex without a condom among participants who have ever had sex
Ever had sex among all participants

Notes

Duration of follow up: 12 months

Loss to follow up: 20%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method on allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Intent‐to‐treat analysis carried out.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Downs 2004

Methods

Randomis ed controlled study. Table of random numbers was used to generate the allocation sequence. Unit of randomis ation: individuals

Participants

300 female part icipants from four urban Pittsburgh area healthcare sites, who were aged 14 years to 18 years and had reported heterosexual vaginal sexual activity in the previous six months, 75% were African American, 15% Whites and 10% other or mixed race

Interventions

Intervention: interactive video intervention on reproductive health/STD education, skills‐ building and contraceptive education delivered for 30 minutes at baseline and 15 minutes on each follow up visit

Control 1: content‐matched control (same intervention in a book form)

Control 2: topic‐matched control (same intervention using commercially available brochures)

Outcomes

Unintended pregnancy, use of condoms, sexually transmitted disease

Notes

Duration of follow up: 6 months

Loss to follow up: 14%

Individuals were randomised to one of the three groups ( interactive video intervention, content‐matched control and topic‐matched control)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Table of random numbers

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

High risk

Only participants who provided data at six months were included in the analysis

Selective reporting (reporting bias)

High risk

Pre‐specifed outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Eisen 1990

Methods

Randomis ed controlled multicentre study. Method used to generate allocation sequence not mentioned in the paper

Unit of randomi sation: individual and classroom

Participants

1444 8th to 9th grade students from six family planning agencies and one school in Texas and California; mean age 15.5 years; 52% female, 48% male; 15% White, 24% African‐American, 53% Hispanic and 8% Asian

Interventions

Intervention: 12 hours to 15 hours on health education (reproductive biology), skills‐ building, contraceptive/STD education

Control: usual sex education programmes which varied among sites

Outcomes

Initiation of intercourse, consistent use of contraceptives

Notes

Duration of follow up: one year

Loss to follow up: 39%

Randomis ation was done individually or by classroom units (71% by classroom and 29% by individual)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Insufficient information to assess this domain

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Fawole 1999

Methods

Cluster‐randomis ed controlled trial. Method used to generate allocation not mentioned in the paper. Unit of randomi sation: classrooms

Participants

450 students from 11 mixed‐sex public schools in Ibadan, Nigeria; mostly Yoruba; 55.2% female, 44.9% male. Low socioeconomic status

Interventions

Intervention: six weekly (each lasted between two hours and six hours) of AIDS/HIV education, health education and contraceptive education

Control: standard curriculum

Outcomes

Initiation of intercourse, use of condoms at last sex, consistent use of condom, sexually transmitted disease

Notes

Duration of follow up: 6 months

Loss to follow up: 3.8%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Participants lost to follow up were less than 5% of the total participants included in the study

Selective reporting (reporting bias)

Low risk

all pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Ferguson 1998

Methods

Cluster‐randomis ed controlled study. Coin toss technique was used to generate allocation sequence
Unit of randomis ation: neighbourhood

Participants

63 female African American students aged 12 years to 16 years who completed the Camp Horizon Adolescent Pregnancy Prevention Program, residing in one of the four public housing developments in Charlottesville, Virginia, not currently pregnant, had never given birth, 5th grade to 10th grade, low income

Interventions

Intervention: two hours per week for eight weeks on health education, skills ‐building, contraceptive education, abstinence, ethnic/cultural values, family options, career counselling by peer counsellors
Control: same interventions taught by usual adult staff

Outcomes

Unintended pregnancy, initiation of intercourse, use of contraceptive at last sex

Notes

Duration of follow up: 3 months.
Loss to follow up: 17%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Tossing a coin

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

High risk

Imbalance in numbers los t to follow up across intervention groups and reasons not stated. Per‐protocol analysis done with substantial departure from one of the groups

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Unclear risk

Baseline differences not reported

Graham 2002

Methods

Cluster‐randomi sed controlled study. Computer‐ generated random numbers used to generate allocation sequence. Unit of randomis ation: schools

Participants

3794 adolescents from secondary schools in Avon, UK , 14 years to 15 years, 52% male, 48% female

Interventions

Intervention: contraception (emergency contraceptives) education

Control: usual sex education

Outcomes

Use of contraceptives, initiation of intercourse

Notes

Duration of follow up: 6 months

Loss to follow up: 18%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated random numbers

Allocation concealment (selection bias)

Unclear risk

No information provided on this domain

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

High risk

Attrition rate > 10%

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Guilamo‐Ramos 2011b

Methods

Randomis ed controlled trial. Dyads (mothers and their adolescents) were randomly assigned. Method of randomis ation was not stated

Participants

2016 adolescents aged 11 years to 14 years, either African American or Hispanic, and accompanied to the clinic by a resident mother

Interventions

Intervention: mothers met with a social work interventionist for 30 minutes and were then given a packet containing reference materials and family activities (teaching parent effective communication and parenting strategies for reducing sexual risk, communication aids) to implement with their daughter at home. They also received two booster calls as a reminder to implement materials.

Control: mothers met with their adolescent's healthcare provider only at the clinic

Outcomes

Vaginal sexual intercourse, frequency of sexual intercourse in the past 30 days and oral sex

Notes

Duration of follow up: 9 months

loss to follow up: 5.4%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Information on this domain was not provided

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

High retention rate (98.6%)

Selective reporting (reporting bias)

Low risk

Reported stated outcome

Other bias

Unclear risk

There was no way of assessing if mothers did implement the intervention at home

Henderson 2007

Methods

Cluster‐randomis ed controlled study. Method used to generate allocation sequence not mentioned in the paper. Unit of randomis ation: schools

Participants

4196 female students in secondary schools in Scotland, 13 years to 15 years,

Interventions

Intervention: SHARE (20 session package: 10 for 3rd year and 10 for 4th years of secondary school respectively) on health/sex education, skills‐ building, contraceptive education primarily through the use of interactive video.

Control: conventional sex education

Outcomes

Childbirth and abortion

Notes

Duration of follow up: 4.5 years

Loss to follow up: 0.5%

One of the control schools demonstrated how to handle condoms (one of the lesson included in the intervention group).

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Information on this domain was not provided

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Minimal participants lost to follow up (0.5%)

Selective reporting (reporting bias)

Low risk

Primary outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Herceg‐Brown 1986

Methods

Randomis ed controlled study. Method used to generate allocation sequence was not mentioned in the paper. Unit of randomis ation:i Individual

Participants

417 female adolescents aged 12 years to 17 years from nine family planning clinics in Philadelphia, making their first visit to the clinics, residing in the area and with a family member. 53% African American, 47% White

Interventions

Intervention 1: Family Support Group ( regular clinic services plus 50 minutes of family or individualis ed counselling services on sex and contraceptive education for six weeks)

Intervention 2: Periodic Support Group ( regular clinic services plus staff supports through two to six telephone calls four to six weeks after initial clinic visit, to monitor teenage adjustment to the contraceptive received at the clinic)

Control Group A and B: regular clinic services

Outcomes

Unintended pregnancy and consistent use of contraceptives

Notes

Duration of follow up: 15 months.

Loss to follow up: 14%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Allocation sequence generation not mentioned

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

High risk

The number of people assessed in each group was not clearly stated

Selective reporting (reporting bias)

Low risk

All pre‐specified outcomes were reported

Other bias

Unclear risk

High rate of non‐compliance among participants randomis ed to the intervention

Howard 1990

Methods

Cluster‐randomi sed controlled study. Method used to generate allocation sequence not mentioned in the paper
Unit of randomis ation: schools

Participants

536 low‐ income minority students from 53 schools in Atlanta, 99% Black, 8th grade to 9th grade

Interventions

Intervention: five sessions on health/STD education, skills‐ building, contraceptive education (first four sessions given fairly close together ‐ four classroom periods in a week or one each week for four weeks; the fifth session given one to three months later)
Control: existing human sexuality programme

Outcomes

Unintended pregnancy, initiation of intercourse

Notes

Duration of follow up: 2 years
Loss to follow up: no mention

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Information on this domain was not provided

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Jemmott 1998

Methods

Randomis ed controlled study. Computer‐ generated random number was used to generate the allocation sequence

Unit of randomis ation: individual

Participants

659 African American students in 6th to 7th grade from three middle schools serving low‐income African American communities in Philadelphia, PA.; mean age of 11.8 years; 53% female and 47% male.

Interventions

Intervention 1: eight 1‐hour modules over two consecutive Saturdays on abstinence HIV intervention (health education, skills‐ building, contraception education with emphasis on abstinence)

Intervention 2: eight 1‐hour modules over two consecutive Saturdays on safer sex HIV intervention (health education, skills‐ building, abstinence with emphasis on the use of contraceptives)

Control: health issues unrelated to sexual behaviour

Each intervention consisted of eight 1‐hour modules divided equally over two consecutive Saturdays

Outcomes

Initiation of intercourse, consistent condom use ( sexual intercourse in past three months among all participants)

Notes

Duration of follow up: 12 months

Loss to follow up: 7.4%

Individuals were randomly allocated to one of the three conditions (abstinence HIV intervention, safer sex HIV intervention and control)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated random numbers

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Proctors were blinded to participants' intervention group

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Per‐protocol analys es were carried out, included only patient present at the end of the study regardless of the number of intervention sessions attended

Selective reporting (reporting bias)

Low risk

All pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Jemmott 2005

Methods

Cluster‐randomis ed controlled study. Computer‐generated random numbers were used to generate allocation sequence. Unit of randomis ation: schools

Participants

682 sexually experienced adolescent girls of a children's hospital, mean age 15.5 years, 68% African American, 32% Hispanic, low income

Interventions

Intervention 1: HIV/STD education, contraceptive education

Intervention 2: skills‐ building, HIV/STD education, contraceptive education

Control: health promotion intervention

Outcomes

Sexually transmitted diseases

Notes

Duration of follow up: 12 months

Loss to follow up: 11.4%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated random numbers

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Attrition was low (11.4%) and did not differ by condition

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Jemmott 2010

Methods

Cluster‐ randomi sed controlled trial using blocked (4 to 8 in size) computer‐generated random number sequences; unit of randomis ation: community‐ based organis ations (CBOs) in a 2 x 3 factorial design to the HIV/STD risk‐reduction intervention or control and to one of the three levels of facilitator training (manual only, standard training and enhanced training)

Participants

1707 adolescents aged 13 years to 18 years who read, wrote and spoke English with written parental or guardian consent in English or Spanish. Over 80% of the participants w ere Black or African American and half of the participants were female

Interventions

Intervention: six 50‐ minute modules of developmentally appropriate interactive activities, films, small group discussions, experimental exercises and role‐play activities. Information provided included the aetiology, detection, transmission, prevention and possibilities of asymptomatic infection, attitudes toward condom use, skill and self‐efficacy in using condoms. It also teaches abstinence as the most effective way to prevent STDs

Manual only: intervention package and no training

Standard training: intervention package and two days' training

Enhanced training: intervention package, two days' standard training and practice implementation of the intervention with group of adolescents

Control: health promotion which focused on reducing behaviours linked to risk for heart disease, hypertension, lung disease and cancer

Outcomes

Self‐reported consistent condom use in the previous three months, proportion of condom‐protected sex, frequency of sex in the past three months, condom use at most recent sex

Notes

Duration of follow up: 3, 6 and 12 months; analysis on condoms and contraceptives were limited to those who were sexually active

loss to follow up: 21.3%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐generated random number sequence

Allocation concealment (selection bias)

Low risk

Facilitators were not aware of which group were in the follow‐up sample and participants were blinded to intervention prior to enrolment

Blinding (performance bias and detection bias)
All outcomes

Low risk

Data collectors were blind to the participant's intervention

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Intention‐to‐treat analysis

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

High risk

Selection bias likely with respect to high decline from CBOs that support abstinence

Kirby 1997a

Methods

Cluster‐randomised controlled trial. Method used to generate allocation sequence not mentioned in the paper. Unit of randomis ation: classrooms

Participants

1657 7th grade students from six schools in California, mean age of 12.3 years; 54% female and 46% male; 64% Hispanic, 13% Asian, 9% African American, 5% non‐ Hispanic , low socio‐economic status

Interventions

Intervention: eight sessions for two weeks on health education, skills ‐building, contraceptive education, risks and consequences of teen sex and community resources

Control: standard curriculum

Outcomes

Unintended pregnancy, initiation of intercourse, use of condoms at last sex, sexually transmitted diseases

Notes

Duration of follow up: 17 months; loss to follow up: 23%

Subset of patients was assessed for certain outcomes such as initiation of intercourse (only students who had never had sex at pre‐test were analys ed); likewise pregnancy and Sexually Transmitted Diseases (STD) (included in the analysis only students who had never been pregnant or never had an STD respectively)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

No information provided. Authors simply stated "randomly assigned"

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

High attrition

Selective reporting (reporting bias)

Low risk

All pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Kirby 1997b

Methods

Randomis ed controlled study. Method of allocation sequence not mentioned in this paper

Unit of randomi sation: schools, agency, classroom, individual

Participants

10,600 youths in 7th grade and 8th grade (mean age of 12.8 years) from schools and community‐based organi sations in California; 58% female and 42% male; 31% Hispanic, 38% White, 9% African‐American

Interventions

Intervention 1: adult‐led intervention ( five sessions, 45‐50 minutes in length, delivered in classrooms or small group settings on health education, skills‐ building, contraceptive education) in addition to the available standard sexuality curriculum, taught by adults

Intervention 2: youth‐led intervention (same intervention taught by peers)

Control: standard sexuality curriculum

Outcomes

Unintended pregnancy, initiation of intercourse, use of condoms, use of hormonal contraceptive, sexually transmitted diseases

Notes

Duration of follow up: 17 months

Loss to follow up: 17%

Five randomis ations were reported (random assignment by classroom to adult‐led intervention, by classroom to youth‐led intervention, by school to adult‐led intervention, by individual to adult‐led intervention, and control)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

High attrition rate

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Unclear risk

The study appears to be free from other sources of bias

Kirby 2004

Methods

Cluster‐randomis ed controlled study. Method used to generate allocation sequence not mentioned in the paper. Unit of randomis ation: schools

Participants

3869 9th grade students from 20 urban high schools in Texas and California who completed the baseline survey in autumn 1993 and officially enrolled at first follow up (spring 1994), mean age 15 years, 53% female and 47% male; 30% White, 27% Hispanic, 18% Asian or Pacific Islanders, 17% Black and 7% other

Exclusion: students who left the school during the 1993 to 1994 school year

Interventions

Intervention: 20 sessions on health education, skills‐ building, contraceptive education, community linkages

Control: standard knowledge‐ based HIV prevention curriculum

Outcomes

Initiation of intercourse, use of contraceptive at last sex

Notes

Duration of follow up: 31 months

Loss to follow up: 21%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Analysis was carried out on the number of students' observations for each outcomes.

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes we re reported

Other bias

Low risk

The study appears to be free from other sources of bias

Kogan 2012

Methods

Randomis ed controlled study; families were randomly assigned

Participants

506 African Americans aged 16 years, with 51% female

Interventions

Intervention: Strong African American Families Teen (SAAF‐T) programme: a family‐ centred intervention made up of five sessions on optimal parenting, preparation for life after high school, content on sexual health, and an optional condom skills unit

Control: family‐ centred intervention but designed to promote healthful behaviours (good nutrition, exercise, and informed consumer behaviour)

Outcomes

Unprotected intercourse in the past three months, condom efficacy

Notes

Duration of follow up: 5 and 22 months

Loss to follow up: 5%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Low attrition rate

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Markham 2012

Methods

Three‐ armed randomis ed controlled trial, schools were randomis ed using a multi‐attribute randomis ation protocol

Participants

1258 students; 75% of students were classified as economically disadvantaged, 59.8% female, 39.3% African American and 48.4% Hispanic with a mean age of 12.6 years

Interventions

Intervention 1 (Risk Avoidance): interactive skills‐training exercises, peer role model videos, emphasis ed interactions between personal, environmental and behavioral influences, beliefs and normative beliefs. it also included homework to facilitate parent‐child communication, incorporating elements of character development and future orientation. It was framed to reinforce abstinence‐until‐marriage beliefs

Intervention 2 (Risk Reduction): contained similar activities as Risk Avoidance but reinforced abstinence‐until‐older beliefs. In addition, it promoted self‐resect and responsibility, activities addressing knowledge and self‐efficacy regarding condom and contraceptive use

Control: regular health classes offered by the respective schools

Outcomes

Sexual initiation (for virgins only), unprotected sex at last vaginal intercourse, frequency of sex in the past three months, frequency of sex without a condom in the past three months, number of lifetime sexual partners, number of sexual partners in the past three months

Notes

Duration of follow up: 16 and 26 months

Loss to follow up: 25%. In addition, 75 students were excluded because of missing or inconsistent responses

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomi sation not clearly explained

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Sample sizes for each outcome varied due to missing data

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes reported

Other bias

Unclear risk

The presence of baseline imbalances in demographics and sexual behaviour between conditions

Mba 2007

Methods

Randomis ed controlled study. Unit of randomisation: individuals; method of randomis ation was not stated

Participants

360 students aged 10 years to 20 years, all African

Interventions

Intervention: reproductive health education on STDs, HIV/AIDS and family planning

Control: no education or intervention

Outcomes

Correct knowledge about STD (control measures), HIV/AIDS (transmission and cure) and family planning (methods and usage)

Notes

Duration of follow up: 6 weeks

Loss to follow up: None

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

High risk

Schools were selected using a basket method of random sampling, while students were selected using a systematic sampling method (every ninth student on the school register)

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Due to the short duration in follow up, no participants were lost and there were no missing outcome data

Selective reporting (reporting bias)

Low risk

All stated outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Minnis 2014

Methods

Cluster‐ randomis ed study; social networks were randomi sed; method of randomis ation not stated but both participants and research interviewers were blinded to the assignment

Participants

162 youths , male and female, aged 16 years to 21 years (median age 16.8) who were Hispanic, residing in San Francisco, spoke English or Spanish, were not pregnant or parenting

Interventions

Intervention: eight life skills sessions (communication and relationship‐ building skills) promoting sexual health with a focus on STI and unintended pregnancy prevention and early childbearing norms; job training, reproductive health wellness (such as clinic visit), cash payment to youth on completion of a given activity

Control: standard community services

Outcomes

Childbearing expectations, STIs, contraceptive self‐efficacy and motivation

Notes

Duration of follow up: 6 months

loss to follow up: 8%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Information on this domain was not provided

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Both participants and research interviewers were blinded to the assignment

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Attrition rate < 10%, baseline differences between participants adherent to the intervention compared to those who did not participate or participated minimally with regards to risky behaviours (lower proportion had ever had sex (< 0.01), gang‐affiliated close friends (< 0.05) and used alcohol frequently (< 0.01)

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Mitchell‐DiCenso 1997

Methods

Cluster‐ randomised controlled trial. Table of random numbers was used to generate allocation sequence

Unit of randomis ation: schools

Participants

3289 students in Grades 7 and 8 in 21 schools in Hamilton, Ontario‐Canada; mean age 12.6 years, 52% female, 48% male, most White

Exclusion: non‐consent by parent or students; planning to move out of the area in the next few weeks; unable to speak or understand English, severe learning disabilities, reached 17th birthday, attendance at a private or separate school

Interventions

Intervention: ten 1‐hour sessions on health education and skills building, media and peer pressure, parenting, teenage pregnancy and responsibility in relationships

Control: conventional sex education

Outcomes

Unintended pregnancy, initiation of intercourse, use of contraceptives

Notes

Duration of follow up: 4 years

Loss to follow up: 44%

During the study, 10 students transferred from the control to the experimental school and one student from an experimental to a control school

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Table of random numbers

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

High rate of attrition by the fourth year with close to half the participants lost to follow up. Analysis for each outcome included only student who responded to that outcome

Selective reporting (reporting bias)

Low risk

Pre‐stated outcomes were reported

Other bias

Unclear risk

Contamination of intervention groups as students who completed Grade 8 moved on to high schools that drew students from a variety of schools, thereby bringing together experimental and control group students

Morberg 1998

Methods

Cluster‐randomised controlled study. Block randomi sation was used to generate allocation sequence. Unit of randomis ation: s chools

Participants

2483 6th grade students in 21 middle schools in small cities and towns in Wisconsin; by 9th grade, participants included 48% male, 52% female, 96% White, 4% other

Interventions

Intervention 1: age‐ appropriate: taught four weeks each year over three years in grade 6, 7 and 8: on social situations, refusal skills (skills‐ building), parental values, media, parent relationship, contraception education, risks, responsibility and sexuality

Intervention 2: intensive; taught as a 12‐ week block in grade 7: same programme

Control: usual curriculum

Outcomes

Initiation of intercourse, use of condoms

Notes

Duration of follow up: 3 years

Loss to follow up: 20%

Students were randomised into one of three interventions ( control, age ‐ appropriate intervention or intensive intervention. One of the seven schools dropped out of the intensive intervention (n = 590), data from these are excluded

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Randomis ation design nested within two self‐selected treatment options

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

No statistical difference between interventions in attrition by 9th grade (p = 0.21). But high percentage of participants were lost to follow up in the 10th grade (32%) and underrepresented the intensive subjects. Individuals were used as the unit of analysis even though clusters were randomised

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Morrison‐Beedy 2013

Methods

Randomis ed controlled trial, individual was randomi sed by block randomi sation, research assistant was blinded to conditions

Participants

738 girls aged 15 years to 19 years, unmarried, not pregnant, not given birth within the past three months, sexually active within the past three months; predominantly low income, 69% African American

Interventions

Intervention: four weekly, 120‐ minute sessions and two 90‐ minute booster sessions at three months and six months post‐intervention. It provided HIV information, motivation to reduce risky behaviour, interpersonal and self‐management and communication skills facilitating sexual risk reduction and condom use

Control: general health promotion (nutrition, breast health, anger management) with the same number of sessions and led by the same facilitators

Outcomes

Frequency of sexual behaviour, protected vaginal sex, number of sexual partners, abstinence

Notes

Duration of follow up: 3 months, 6 months and 12 months

Loss to follow up: approx 14%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Block randomi sation of participants, but method of block randomi sation not stated

Allocation concealment (selection bias)

Unclear risk

No information on this domain was provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Condition was known only to the project director until each group was filled and facilitators assigned. Also, pregnancy and STI was confirmed by testing

Incomplete outcome data (attrition bias)
All outcomes

High risk

Attrition rate: 14%; Girls lost to follow up were older and may have been at more risk of the outcomes

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Norton 2012

Methods

Randomi sed controlled trial; method of randomis ation not stated

Participants

198 college students that were at least 18 years of age, heterosexual, engaged in sexual intercourse at least once during the past three months; 70% females, 85% White and 15% non‐ White

Interventions

Intervention: it includes information and myths, attitudes and social norms, teaching skills and building self‐efficacy regarding increasing condom use and safer sexual behaviour. with an exclusive focus on preventing unplanned pregnancy (Intervention A), STI (Intervention B) or HIV infection (Intervention C).

Control: standard healthcare services received by students in college settings

Outcomes

Condom use, including percentage, frequency and use at last sex; number of unprotected vaginal intercourse

Notes

Duration of follow up: 4 weeks and 8 weeks; for certain outcomes, the different interventions were collapsed as one

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomis ation not stated

Allocation concealment (selection bias)

Unclear risk

No information on this domain was provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

No information on this domain was provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Attrition rates were not reported

Selective reporting (reporting bias)

Low risk

All stated outcomes w ere reported

Other bias

Low risk

The study appears to be free from other sources of bias

O'Donnell 1999

Methods

Cluster‐ randomis ed controlled trial. Classrooms within the intervention school were randomly assigned

Participants

1061 minority students, 7th & 8th graders, 79.2% African American, 47.2% male and 15.9% Hispanic, high‐risk health profile, high‐risk academic profile, with limited access to resources

Interventions

Intervention: the intervention was split into two; the regular community youth service (CYS) classroom curriculum (40 lessons in 7th grade and 34 lessons in 8th grade on risk related to early and unprotected sex, violence, substance use, healthy development and sexuality) and CYS classroom curriculum enhanced by participation. In the latter, participants engaged in three hours per week community placement performing a variety of tasks associated with social skills and behaviours, assisting or observing doctors, recreation groups etc

Control: intervention not explained

Outcomes

Initiation of sex (virgins at baseline), recent sex in the last three months, use of protection during the most recent intercourse

Notes

Duration of follow up: 6 months

loss to follow up: 8.3%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomi sation was not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Low loss to follow up (< 10%)

Selective reporting (reporting bias)

Low risk

All outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

O'Donnell 2002

Methods

Cluster‐randomis ed controlled study. Method used to generate allocation sequence not stated. Unit of randomis ation: classrooms

Participants

225 7th grade students from 18 classrooms attending a public middle school in New York, 71% non‐Hispanic African‐American, 26% Hispanic, low socio‐economic status

Interventions

Intervention: thr ee hours per week Community Youth Service (CYS) plus classroom curriculum (40 lessons in 7th grade and 34 lessons in 8th grade on risk related to early and unprotected sex, violence, substance use, healthy development and sexuality)

Control: standard classroom curriculum

Outcomes

Pregnancy among all participants not reporting pregnancy at baseline
Ever had sex among all participants

Notes

Duration of follow up: 4 years

Loss to follow up: 23%

After year 1 of the programme, the school expanded the CYS component to more students resulting in 32 students transferring into the intervention group and 16 transferring to the control group because CYS did not fit their schedules. Analyses were divided into youths receiving two programme years, youths receiving one programme year (i.e. those who transferred in or out after year 1), and no‐exposure controls.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Irrespective of the crossover of participants between intervention and control groups, analysis retained participants in their previous randomised group

Selective reporting (reporting bias)

Low risk

Pre‐specifed outcomes were reported

Other bias

Unclear risk

Crossover of students between groups could have contaminated the different groups.

Okonofua 2003

Methods

Cluster‐randomised controlled study. Method used to generate allocation sequences not mentioned. Unit of randomis ation: schools

Participants

1896 students in secondary schools in Benin, Nigeria, 14 years to 20 years, 53% female, 47% male, 33% Ishan, 36% Bini, 5% Yoruba, 10% Ibo, 16% other

Interventions

Health education, peer education on STD, individual or group counselling by trained peer educators, training of health providers on STD diagnosis and treatment around the intervention schools

Control: no intervention

Outcomes

Use of condoms

Notes

Duration of follow up: 10 months

Loss to follow up: 1%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not mentioned

Allocation concealment (selection bias)

Unclear risk

Information on this domain was not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Individuals were used as the unit of analysis even though clusters (classrooms) were randomised.

All participants lost to follow up were from the control group and per‐protocol analysis used

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Perskin 2015

Methods

Two‐arm nested randomis ation design. Randomi sation was carried out using a Multi‐attribute randomi sation method. Unit of randomi sation: s chools

Participants

1571 female participants with mean age of 14.3 years (standard deviation = 0.59), and was 59% female, 74% Hispanic, 17% African‐American, and 9% other race/ethnicity. Close to 20% of students reported ever engaging in any type of sex (vaginal, oral, or anal)

Interventions

Intervention: computer‐based sexual health education, animated scenario with modelling and skills practices, peer‐modelling videos, quizzes, virtual role‐playing activities to stimulate student skills practice in real‐world situation, healthy/unhealthy dating relationship, anatomy of reproduction, social, emotional, physical consequences of sex, communication skills, internet communication safety, causes of teen pregnancies and STIs, knowledge and skills of condoms and contraception use and condom negotiation

Control: state‐approved school health education

Outcomes

Delayed initiation of any sexual activity, sexual behaviours such as use of condoms in the past three months and last sex, number of partners at different time points, knowledge of STIs and condoms, and beliefs (psychosocial measures)

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Multi‐attribute randomi sation method

Allocation concealment (selection bias)

Unclear risk

Method not stated but it was stated that "participants were blinded to condition during allocation"

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain was not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Attrition rate approx. 10%, which was similar across groups

Selective reporting (reporting bias)

High risk

Primary outcome was reported. However, most of the secondary pre‐specified outcomes such as condom use at last sex or in the last three months were not reported

Other bias

Low risk

The study appears to be free from other sources of bias

Philliber 2002

Methods

Randomis ed controlled study. Unit of randomi sation: individual

Participants

484 teenagers in New York not currently pregnant or a parent, 13 years to 15 years, 55% female, 45% male, 56% Black, 42% Hispanic, 2% other

Interventions

Intervention: job clubs, academic skills, family and life sexuality education, developing personal art skills, recreational activities, group/individual counselling, contraceptive education, medical care ( five days per week for a school year)

Control: alternative youth programme (recreational activities, homework help, art and crafts)

Outcomes

Unintended pregnancy, childbirth, initiation of intercourse, use of condoms at last sex

Notes

Duration of follow up: 3 years

Loss to follow up: 21%

Allocation concealment by the use of opaque envelopes

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomis ation not stated

Allocation concealment (selection bias)

Low risk

Use of opaque envelopes

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Analysis was based on number of participants present at the end of the three ‐year follow up (high attrition rate)

Selective reporting (reporting bias)

Low risk

Pre‐specfied outcomes reported

Other bias

Unclear risk

Possible contamination (exchange of information) between groups, since both programmes were conducted at the same site

Raine 2005

Methods

Randomis ed controlled study. Computer‐generated randomi sation sequence was used.

Unit of randomi sation: individual

Participants

2117 women attending four California clinics providing family planning services, who were not desiring pregnancy, 15 years to 24 years (mean 19.9), spoke English or Spanish, had sexual intercourse in the past six months, using long‐ term hormonal contraception or requesting EC, 20% Hispanic, 15% Black, 31% White, 22% Asian, 12% Other

Interventions

intervention 1: pharmacy access group (instructions for obtaining levonorgestrel

Intervention 2: (provision of three packets of levonorgestrel EC and its dosage)

Control: clinic access (instructions to return to the clinic for EC, if needed)

Outcomes

Unintended pregnancy, contraceptive use (consistent condom use, use of hormonal contraceptives, use of condom at last sex), sexually transmitted diseases

Notes

Duration of follow up: 6 months

Loss to follow up: 8%

Single blinding ( research staff only)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated numbers

Allocation concealment (selection bias)

Low risk

Sealed, sequential numbered boxes identical in appearance were used to conceal allocation

Blinding (performance bias and detection bias)
All outcomes

Low risk

Research staff only

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Use of a Modified intention‐to treat where only participants who completed follow‐up in their respective randomised group were analys ed. Attrition analysis showed no difference in characteristics of women lost to follow up.

Selective reporting (reporting bias)

Low risk

All stated outcomes in the method section were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Raymond 2006

Methods

Randomis ed controlled study. Computer‐ generated random numbers were used in allocation sequence. Unit of randomis ation: individuals

Participants

1490 sexually active women not desiring pregnancy, 14 years to 24 years, 13% Hispanic, 70% White, 21% non‐ White

Interventions

Intervention: contraception distribution ( two packages of pills dispensed in advance with unlimited resupply at no charge)

Control: contraceptive distribution (pills dispensed when needed at usual charge)

Outcomes

Unintended pregnancy, sexually transmitted diseases

Notes

Duration of follow up: 1 year

Loss to follow up: < 7%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated number

Allocation concealment (selection bias)

Low risk

Sealed opaque envelopes

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

All randomised participants were included in the analysis

Selective reporting (reporting bias)

Low risk

Pre‐specified outcome reported

Other bias

Unclear risk

Higher proportion of people in the increased access group had a sexually transmitted disease which may lead to increased use of condoms

Shrier 2001

Methods

Randomis ed controlled trial. Table of random numbers was used to generate allocation sequence. Unit of randomis ation: individuals

Participants

123 female participants between the ages of 13 years to 22 years (median 17.2) with cervicitis or pelvic inflammatory disease in urban children's hospital, adolescent clinic and inpatient service in Boston, 49% non‐Hispanic Black, 18% Hispanic, 14% Non‐Hispanic White, 17% other

Exclusion: p atient had treatment of STDs between laboratory confirmation; patient pregnant at treatment visit; patient already exposed to intervention through pilot study

Interventions

Intervention: watch a seven ‐minute videotape featuring contraception education (condoms), contraception distribution, individual counselling on risk perception, STD education, pregnancy prevention and consequences of unprotected sex and a booster session at one , three and six months.

Control: standard STD education and contraceptive education and distribution

Outcomes

Sexually transmitted diseases

Notes

Duration of follow up: 12 months

Loss to follow up: 48%

Assessors were blinded to participant allocation

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Table of random numbers

Allocation concealment (selection bias)

Unclear risk

Information on this domain not provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Assessors only

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

High attrition rates of over 20% though it did not differ between the intervention and control groups. As‐treated analysis was done with substantial loss‐ to‐ follow‐ up of participants across groups.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

Study appears to be free from other sources of bias

Sieving 2011

Methods

Randomis ed controlled trial. Individuals were randomi sed to the intervention or control but the method of randomi sation was not stated.

Participants

253 girls aged between 13 years to 17 years, racially mixed ; American Indian, Asian, Hispanic, White/European, mixed and Black/African/African American. Black/African/African American made up over 40% of the population

Interventions

Intervention: one‐on‐one case management addressing the following issues: emotional skills, healthy relationships, responsible sexual behaviours, positive family, school and community involvement and the peer leadership components which provided hands‐on skills‐ building experiences; plus usual clinic services

Control: usual clinic services

Outcomes

Contraceptive use (condom, hormonal and dual method) consistency with most recent sex partner, number of sex partners in the past six months

Notes

Duration of follow up: ,12 & 24 months, intention‐to‐treat design

Loss to follow up: 5.5% and 6.7% at 12 and 24 months respectively

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomis ation not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain not provided

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Attrition rate was low (< 10%)

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes not provided

Other bias

Low risk

The study seems to be free from other sources of bias

Smith 1994

Methods

Randomis ed controlled study. Method used to generate allocation sequence not mentioned in the paper. Unit of randomis ation: individuals

Participants

120 9th grade students from the 1989 class of freshmen at a high school in Queens, New York. Mean age 15.1 years; 74.2% female and 25.8% male; 43.3% African American, 30.8% West Indian, 22.5% Hispanic and 3.3% other

Interventions

Intervention: one session per week for 14 weeks on health/STD education, skills‐ building, contraceptive education and individual counselling on career mentorship

Control: written materials on contraception and decision making pertaining to sexual‐ and fertility‐ related risk‐taking behaviour

Outcomes

Initiation of intercourse ( absolute sexual frequency ‐ instances of completed sexual activity during past two months, among all participants)

Notes

Duration of follow up: six months.

Loss to follow up: 21%

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of allocation sequence generation not stated

Allocation concealment (selection bias)

Unclear risk

No information provided on this domain

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

No information provided on this domain

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Per‐protocol analysis was done with substantial departure of the intervention received from that assigned at randomis ation

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Stephenson 2004

Methods

Cluster‐randomis ed controlled study. Schools were randomised within strata, using a computer‐generated sequence of allocation of block size ten. Unit of randomis ation: schools

Participants

8766 pupils in 29 schools in central and southern England, aged 13 years to 14 years; over 9000 pupils

Interventions

Intervention: Three 1‐hour sessions on sexual communication and relationships, contraceptive education (condoms) (pressure role play on declining sex or insisting on the use of condoms), HIV/STD education (transmission and treatment) taught by peer leaders (16 years to 17years)

Control: usual teacher‐led sex education

Outcomes

Unintended pregnancy, heterosexual intercourse at age 16 years, use of contraceptives (at first and last sex), use of condoms, abortion and livebirth at age 20 years, self‐reported STD

Notes

Duration of follow up: 18 months and 54 months

Loss to follow up: 14% and > 40% at 18 months and 54 months respectively

Data on abortion and livebirth are included in data & analysis, while others are reported in additional tables

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐generated sequence of allocation of block size ten

Allocation concealment (selection bias)

Unclear risk

No information provided on this domain

Blinding (performance bias and detection bias)
All outcomes

Low risk

While blinding of participants/facilitators to allocation was not possible, matching of outcomes to sources was blinded

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

All participants who experienced the outcome at baseline and who completed at least one follow‐up questionnaire were included in the analysis for the primary outcome (initiation of intercourse). High attrition rate at 54 months but intention ‐to‐ treat was employed for primary outcomes (childbirth and abortion by 20 years) at the second follow up

Selective reporting (reporting bias)

Low risk

Expected outcomes and those pre‐specified in the methods were reported

Other bias

Unclear risk

It is not known for sure if there was no contamination between pupils in the different groups

Villarruel 2006

Methods

Randomised controlled study. Computer‐generated random numbers used to generate allocation sequence

Unit of randomi sation: individuals

Participants

656 8th grade to 11th grade students in Northeast Philadelphia schools and community‐ based organis ations, aged 13 years to 18 years, 45% male, 55% female, 85.4% Hispanic

Interventions

Intervention: six 50‐minute modules on Health/HIV education, skills‐ building, contraceptive education

Control: health promotion education

Outcomes

Initiation of intercourse in the past t hree months, consistent condom use in the past three months,

Notes

Duration of follow up: 12 months

Loss to follow up: 13%

103 students were excluded from the analysis because they were non‐ Hispanic

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Computer‐ generated numbers

Allocation concealment (selection bias)

Unclear risk

No information provided on this domain

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

No information provided on this domain

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Analyse s were conducted using an intention‐to‐treat approach in which participants were analy sed in their original randomised groups regardless of the number of sessions attended

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes were reported

Other bias

Low risk

The study appears to be free from other sources of bias

Walker 2006

Methods

Cluster‐randomis ed controlled study. Method used to generate allocation sequence not mentioned in the paper. Unit of randomi sation: schools

Participants

10,954 10th grade to 12th grade high school students in Morelos, 15 years to 18 years, 48% male, 52% female

Interventions

Intervention 1: HIV education, skills‐ building, cultural values, contraceptive promotion ( condoms).

Intervention 2: HIV education, skills‐ building, cultural values plus contraceptive education (EC plus condoms and their access).

Control: biology‐ based sex education

Outcomes

Initiation of intercourse, use of condom at last sex, use of hormonal contraceptive

Notes

Duration of follow up: 16 months

Loss to follow up: 33.3%

Two of the intervention schools were included in the control group because they did not teach the intervention course

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

The statement "randomly assigned" was said but the method of allocation generation was not stated.

Allocation concealment (selection bias)

Unclear risk

Information on this domain not provided

Blinding (performance bias and detection bias)
All outcomes

Unclear risk

Information on this domain not provided

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Per‐protocol analysis was done. But analysis took the cluster sample design into account.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes not provided

Other bias

Low risk

The study appears to be free from other sources of bias

Wight 2002

Methods

Cluster‐randomis ed controlled study. Method used to generate allocation sequence not mentioned. Unit of randomi sation: schools

Participants

7616 pupils from 25 secondary schools in east Scotland, 13 years to 15 years, 50% male, 50% female

Interventions

Intervention: SHARE (20‐ session package: 10 for 3rd years and 10 for 4th years of secondary school respectively) on health/sex education, skills ‐building, contraceptive education primarily through the use of interactive video

Control: conventional sex education

Outcomes

Unintended pregnancy, initiation of intercourse, use of condoms at last sex

Notes

Duration of follow up: 2 years

Loss to follow up: 31%

Single blinding ( assessors)

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Method of randomis ation was not stated

Allocation concealment (selection bias)

Unclear risk

Information on this domain not provided

Blinding (performance bias and detection bias)
All outcomes

Low risk

Assessors only

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Outcomes were analy sed based on the number of participants at the end of the two ‐year follow up.

Selective reporting (reporting bias)

Low risk

Pre‐specified outcomes reported

Other bias

Low risk

The study appears to be free from other sources of bias

Characteristics of excluded studies [ordered by study ID]

Study

Reason for exclusion

Agha 2002

Did not measure any of the desired outcomes

Amin 2004

Randomi sed controlled trial but participants were pregnant or parenting teens

Antunes 2002

Participants above the required age range

Barlow 2006

Had none of the required interventions

Barnet 2009

Secondary prevention of adolescent pregnancy

Barnet 2010

Unintended repeat pregnancies assessed

Bonell 2005

No specified intervention

Bouris 2010

Non‐randomis ed controlled trial

Boyer 2005

Participants above the required age range

Brinkman 2010

Published protocol

Brown 2011

Control group received an intervention aimed at promoting contraceptive usage

Buston 2007

Non‐randomis ed controlled trial

Cagampang 1997

Non‐randomis ed controlled trial

Chesney 2003

Non‐randomis ed controlled trial

Chung‐Park 2008

Participants aged 18 years to 32 years (above required age range)

Cowan 2008

Reported information on baseline characteristics only

Crosby 2005

None of the desired outcomes was measured

Danielson 1990

Quasi‐experimental study

Decat 2014

C ross‐sectional st udy

Di 2004

None of the desired outcomes was measured

Diclemente 2001

Non‐randomis ed controlled study

Doniger 2001

Non‐randomis ed controlled study

Dycus 1990

Non‐randomis ed controlled study

East 2003

Non‐randomis ed controlled study

Eisen 1985

Non‐randomis ed controlled study

Eisen 1987

Non‐randomis ed controlled study

El‐Bassel 2003

Participants were above the required age range

Ferguson 1998

Quasi‐randomis ed controlled study

Fitzgerald 2002

Non‐randomis ed controlled study

Gallegos 2008

Did not measure any of the desired outcomes

Garbers 2012

Participants above the required age and different outcomes measured

Gaughran 2014

Non‐randomis ed controlled trial

Guilamo‐Ramos 2011a

No control group

Harvey 2004

Randomis ed controlled trial but participants included couples only

Havens 1997

Unintended repeat pregnancies assessed

Howard 1990

Non‐randomi sed controlled trial

Hutchinson 2003

None of the desired outcomes was measured

James 2005

Participant above the required age range

Jay 1984

Did not measure any of the desired outcomes

Jennings 2014

Non‐randomis ed controlled trial

Jewkes 2006

Participants above the required age range

Kaljee 2005

None of the desired outcomes was measured

Kamali 2002

Age range above the required range

Katz 2011

Unintended repeat pregnancies assessed

Kirby 2002a

A Review

Kirby 2002c

Non‐randomis ed controlled trial

Kuroki 2008

An epidemiological study

Kyrychenko 2006

Non‐randomis ed controlled study

Legardy 2005

Participants' age range was above the required range

Liberman 2000

Non‐randomis ed controlled study

Magnani 2005

Non‐randomis ed controlled trial

Martiniuk 2003

Study did not measure any of the desired outcomes

Matteson 2006

No intervention

McBride 2000

Method of randomis ation not adequate

Metcalf 2005

Participants were above the required age range

Mitchell 2014

Non‐randomis ed controlled trial

O'Donnell 2005

None of the desired outcomes was measured

Ochiogu 2011

Non‐randomis ed controlled trial

Olsen 1991

Not a randomis ed controlled trial

Padian 2007

Participants above the required age range

Peipert 2008

Participants above the required age range

Peipert 2011

Participants above the required age range

Peipert 2012

Not a randomis ed controlled trial

Peragallo 2005

Participants above the required age range

Peterson 2007

Participants above the required age range

Proude 2004

Participants above the required age range

Rickert 2007

Participants above the required age range

Robin 2004

A review

Schreiber 2010

Unintended repeat pregnancies assessed

Schwarz 2008

Participants above the required age range

Secura 2014

Non‐randomis ed controlled trial

Shuey 1999

A quasi‐randomis ed study

Sieving 2012

Non‐randomis ed controlled trial

Silva 2002

A review

Stout 1989

A review

Thato 2008

Quasi‐experimental design

Thomas 2000

A review

Thomas 2004

Non‐randomis ed controlled trial

Tingle 2002

Non‐randomis ed controlled trial

Van 1985

Study included participants greater than the age limit and it was not clearly stated what percentage was within the accepted age range

Van Devanter 2002

Participants were not within the age limit

Wiggins 2009

Case‐control study

Yoo 2004

Non‐randomis ed study

Zabin 1986

Non‐randomis ed study

Zabin 1988

Non‐randomis ed study

Zimmerman 2008

Quasi‐experimental study

Characteristics of studies awaiting assessment [ordered by study ID]

Murray 2015

Methods

Multi‐center, clinic‐based, randomised controlled trial

Participants

Female, aged 14 years to 19 years

Interventions

Seventeen Days (theory‐based interactive video intervention)

Outcomes

Unintended pregnancy and STIs

Notes

Full paper pending

Shafii 2014

Methods

Randomised controlled study

Participants

Male and female (14 years to 24 years)

Interventions

Interactive computer‐based intervention

Outcomes

STIs, unintended pregnancy, number of partners, rate of unprotected vaginal sex (without condoms) and rate of unprotected vaginal sex (without contraceptive)

Notes

Full paper pending

Data and analyses

Open in table viewer
Comparison 1. Multiple interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy [individually randomised trials] Show forest plot

4

1905

Risk Ratio (M‐H, Fixed, 95% CI)

0.66 [0.50, 0.87]

Analysis 1.1

Comparison 1 Multiple interventions, Outcome 1 Unintended pregnancy [individually randomised trials].

Comparison 1 Multiple interventions, Outcome 1 Unintended pregnancy [individually randomised trials].

2 Unintended pregnancy [cluster‐randomised trials] Show forest plot

5

3149

Risk Ratio (M‐H, Random, 95% CI)

0.50 [0.23, 1.09]

Analysis 1.2

Comparison 1 Multiple interventions, Outcome 2 Unintended pregnancy [cluster‐randomised trials].

Comparison 1 Multiple interventions, Outcome 2 Unintended pregnancy [cluster‐randomised trials].

3 Initiation of sexual intercourse ‐ individually RCT Show forest plot

4

1796

Risk Ratio (M‐H, Random, 95% CI)

0.99 [0.74, 1.32]

Analysis 1.3

Comparison 1 Multiple interventions, Outcome 3 Initiation of sexual intercourse ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 3 Initiation of sexual intercourse ‐ individually RCT.

4 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

7

8608

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.68, 1.04]

Analysis 1.4

Comparison 1 Multiple interventions, Outcome 4 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 4 Initiation of sexual intercourse ‐ cluster RCT.

5 Use of birth control methods ‐ individually RCT Show forest plot

8

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

Analysis 1.5

Comparison 1 Multiple interventions, Outcome 5 Use of birth control methods ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 5 Use of birth control methods ‐ individually RCT.

5.1 Condom use in last sex

3

796

Risk Ratio (M‐H, Random, 95% CI)

1.00 [0.95, 1.06]

5.2 Consistent condom use

5

1681

Risk Ratio (M‐H, Random, 95% CI)

1.21 [0.95, 1.54]

5.3 Contraceptive use at last sex

1

408

Risk Ratio (M‐H, Random, 95% CI)

0.99 [0.95, 1.03]

5.4 Consistent contraceptive use

1

253

Risk Ratio (M‐H, Random, 95% CI)

1.29 [1.06, 1.59]

6 Use of birth control methods ‐ cluster RCT Show forest plot

6

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

Analysis 1.6

Comparison 1 Multiple interventions, Outcome 6 Use of birth control methods ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 6 Use of birth control methods ‐ cluster RCT.

6.1 Condom use at last sex

4

2620

Risk Ratio (M‐H, Random, 95% CI)

1.01 [0.93, 1.09]

6.2 Consistent condom use

3

826

Risk Ratio (M‐H, Random, 95% CI)

1.95 [0.70, 5.44]

6.3 Hormonal contraceptives

3

3987

Risk Ratio (M‐H, Random, 95% CI)

1.01 [0.72, 1.43]

7 Sexually Transmitted Diseases ‐ individually RCT Show forest plot

2

699

Risk Ratio (M‐H, Fixed, 95% CI)

0.89 [0.65, 1.22]

Analysis 1.7

Comparison 1 Multiple interventions, Outcome 7 Sexually Transmitted Diseases ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 7 Sexually Transmitted Diseases ‐ individually RCT.

8 Sexually Transmitted Diseases ‐ cluster RCT Show forest plot

2

420

Risk Ratio (M‐H, Fixed, 95% CI)

0.76 [0.27, 2.14]

Analysis 1.8

Comparison 1 Multiple interventions, Outcome 8 Sexually Transmitted Diseases ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 8 Sexually Transmitted Diseases ‐ cluster RCT.

9 Childbirth ‐ cluster RCT Show forest plot

1

4776

Odds Ratio (M‐H, Fixed, 95% CI)

0.64 [0.52, 0.79]

Analysis 1.9

Comparison 1 Multiple interventions, Outcome 9 Childbirth ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 9 Childbirth ‐ cluster RCT.

10 Childbirth ‐ individually RCT Show forest plot

1

484

Risk Ratio (M‐H, Fixed, 95% CI)

0.67 [0.31, 1.45]

Analysis 1.10

Comparison 1 Multiple interventions, Outcome 10 Childbirth ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 10 Childbirth ‐ individually RCT.

11 Second unintended pregnancy ‐ individually RCT Show forest plot

1

149

Risk Ratio (M‐H, Fixed, 95% CI)

0.48 [0.22, 1.02]

Analysis 1.11

Comparison 1 Multiple interventions, Outcome 11 Second unintended pregnancy ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 11 Second unintended pregnancy ‐ individually RCT.

12 Abortion (cluster RCT) Show forest plot

1

4776

Odds Ratio (M‐H, Fixed, 95% CI)

0.93 [0.72, 1.21]

Analysis 1.12

Comparison 1 Multiple interventions, Outcome 12 Abortion (cluster RCT).

Comparison 1 Multiple interventions, Outcome 12 Abortion (cluster RCT).

Open in table viewer
Comparison 2. Sensitivity analysis [Multiple interventions]: Unintended pregnancy

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy ‐ cluster‐randomi sed trials Show forest plot

2

497

Risk Ratio (M‐H, Random, 95% CI)

0.20 [0.10, 0.39]

Analysis 2.1

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 1 Unintended pregnancy ‐ cluster‐randomi sed trials .

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 1 Unintended pregnancy ‐ cluster‐randomi sed trials .

2 Unintended pregnancy ‐ individually‐randomi sed trials Show forest plot

3

1421

Odds Ratio (M‐H, Fixed, 95% CI)

0.68 [0.46, 1.00]

Analysis 2.2

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 2 Unintended pregnancy ‐ individually‐randomi sed trials .

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 2 Unintended pregnancy ‐ individually‐randomi sed trials .

3 Unintended pregnancy ‐ cluster‐adjusted + individual Show forest plot

5

1918

Risk Ratio (M‐H, Fixed, 95% CI)

0.53 [0.39, 0.72]

Analysis 2.3

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 3 Unintended pregnancy ‐ cluster‐adjusted + individual .

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 3 Unintended pregnancy ‐ cluster‐adjusted + individual .

Open in table viewer
Comparison 3. Sensitivity analysis [Multiple interventions]: Initiation of intercourse

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Initiation of sexual intercourse ‐ individually RCT Show forest plot

3

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

Analysis 3.1

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 1 Initiation of sexual intercourse ‐ individually RCT.

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 1 Initiation of sexual intercourse ‐ individually RCT.

1.1 Gender mixed or not specified

3

1312

Risk Ratio (M‐H, Random, 95% CI)

1.18 [0.67, 2.09]

2 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

4

1687

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.57, 1.25]

Analysis 3.2

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

2.1 Gender mixed or not specified

4

1687

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.57, 1.25]

3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual Show forest plot

7

2999

Odds Ratio (M‐H, Fixed, 95% CI)

0.88 [0.74, 1.05]

Analysis 3.3

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual.

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual.

3.1 Gender mixed or not specified

7

2999

Odds Ratio (M‐H, Fixed, 95% CI)

0.88 [0.74, 1.05]

Open in table viewer
Comparison 4. Educational interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

2

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

Analysis 4.1

Comparison 4 Educational interventions , Outcome 1 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 4 Educational interventions , Outcome 1 Initiation of sexual intercourse ‐ cluster RCT.

1.1 Gender mixed or not specified

2

672

Risk Ratio (M‐H, Fixed, 95% CI)

0.95 [0.71, 1.27]

2 Use of birth control methods ‐ cluster RCT Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

Analysis 4.2

Comparison 4 Educational interventions , Outcome 2 Use of birth control methods ‐ cluster RCT.

Comparison 4 Educational interventions , Outcome 2 Use of birth control methods ‐ cluster RCT.

2.1 condom use at last sex

2

1431

Risk Ratio (M‐H, Random, 95% CI)

1.18 [1.06, 1.32]

3 Use of contraceptives ‐ individually RCT Show forest plot

1

360

Risk Ratio (M‐H, Fixed, 95% CI)

2.5 [1.39, 4.48]

Analysis 4.3

Comparison 4 Educational interventions , Outcome 3 Use of contraceptives ‐ individually RCT.

Comparison 4 Educational interventions , Outcome 3 Use of contraceptives ‐ individually RCT.

Open in table viewer
Comparison 5. Contraceptive‐promoting interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy ‐ individually RCT Show forest plot

2

3440

Risk Ratio (M‐H, Fixed, 95% CI)

1.01 [0.81, 1.26]

Analysis 5.1

Comparison 5 Contraceptive‐promoting interventions, Outcome 1 Unintended pregnancy ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 1 Unintended pregnancy ‐ individually RCT.

2 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

1

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

Analysis 5.2

Comparison 5 Contraceptive‐promoting interventions, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

2.1 Female

1

1446

Risk Ratio (M‐H, Fixed, 95% CI)

0.89 [0.76, 1.04]

2.2 Male

1

1560

Risk Ratio (M‐H, Fixed, 95% CI)

1.02 [0.87, 1.21]

3 Use of birth control methods ‐ cluster RCT Show forest plot

1

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

Analysis 5.3

Comparison 5 Contraceptive‐promoting interventions, Outcome 3 Use of birth control methods ‐ cluster RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 3 Use of birth control methods ‐ cluster RCT.

3.1 Hormonal contraceptives

1

415

Risk Ratio (M‐H, Fixed, 95% CI)

0.90 [0.69, 1.18]

4 Use of birth control methods ‐ individually RCT Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

Analysis 5.4

Comparison 5 Contraceptive‐promoting interventions, Outcome 4 Use of birth control methods ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 4 Use of birth control methods ‐ individually RCT.

4.1 Condom use in last sex

2

3091

Risk Ratio (M‐H, Random, 95% CI)

0.95 [0.87, 1.04]

4.2 Consistent condom use

1

1950

Risk Ratio (M‐H, Random, 95% CI)

0.90 [0.71, 1.15]

4.3 Hormonal contraceptives

2

3091

Risk Ratio (M‐H, Random, 95% CI)

2.22 [1.07, 4.62]

5 Sexually Transmitted Diseases ‐ individually RCT Show forest plot

2

3440

Risk Ratio (M‐H, Fixed, 95% CI)

0.92 [0.75, 1.13]

Analysis 5.5

Comparison 5 Contraceptive‐promoting interventions, Outcome 5 Sexually Transmitted Diseases ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 5 Sexually Transmitted Diseases ‐ individually RCT.

Risk of bias summary: review authors' judgments about each risk of bias item for each included study.
Figuras y tablas -
Figure 1

Risk of bias summary: review authors' judgments about each risk of bias item for each included study.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
Figuras y tablas -
Figure 2

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Comparison 1 Multiple interventions, Outcome 1 Unintended pregnancy [individually randomised trials].
Figuras y tablas -
Analysis 1.1

Comparison 1 Multiple interventions, Outcome 1 Unintended pregnancy [individually randomised trials].

Comparison 1 Multiple interventions, Outcome 2 Unintended pregnancy [cluster‐randomised trials].
Figuras y tablas -
Analysis 1.2

Comparison 1 Multiple interventions, Outcome 2 Unintended pregnancy [cluster‐randomised trials].

Comparison 1 Multiple interventions, Outcome 3 Initiation of sexual intercourse ‐ individually RCT.
Figuras y tablas -
Analysis 1.3

Comparison 1 Multiple interventions, Outcome 3 Initiation of sexual intercourse ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 4 Initiation of sexual intercourse ‐ cluster RCT.
Figuras y tablas -
Analysis 1.4

Comparison 1 Multiple interventions, Outcome 4 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 5 Use of birth control methods ‐ individually RCT.
Figuras y tablas -
Analysis 1.5

Comparison 1 Multiple interventions, Outcome 5 Use of birth control methods ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 6 Use of birth control methods ‐ cluster RCT.
Figuras y tablas -
Analysis 1.6

Comparison 1 Multiple interventions, Outcome 6 Use of birth control methods ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 7 Sexually Transmitted Diseases ‐ individually RCT.
Figuras y tablas -
Analysis 1.7

Comparison 1 Multiple interventions, Outcome 7 Sexually Transmitted Diseases ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 8 Sexually Transmitted Diseases ‐ cluster RCT.
Figuras y tablas -
Analysis 1.8

Comparison 1 Multiple interventions, Outcome 8 Sexually Transmitted Diseases ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 9 Childbirth ‐ cluster RCT.
Figuras y tablas -
Analysis 1.9

Comparison 1 Multiple interventions, Outcome 9 Childbirth ‐ cluster RCT.

Comparison 1 Multiple interventions, Outcome 10 Childbirth ‐ individually RCT.
Figuras y tablas -
Analysis 1.10

Comparison 1 Multiple interventions, Outcome 10 Childbirth ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 11 Second unintended pregnancy ‐ individually RCT.
Figuras y tablas -
Analysis 1.11

Comparison 1 Multiple interventions, Outcome 11 Second unintended pregnancy ‐ individually RCT.

Comparison 1 Multiple interventions, Outcome 12 Abortion (cluster RCT).
Figuras y tablas -
Analysis 1.12

Comparison 1 Multiple interventions, Outcome 12 Abortion (cluster RCT).

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 1 Unintended pregnancy ‐ cluster‐randomi sed trials .
Figuras y tablas -
Analysis 2.1

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 1 Unintended pregnancy ‐ cluster‐randomi sed trials .

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 2 Unintended pregnancy ‐ individually‐randomi sed trials .
Figuras y tablas -
Analysis 2.2

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 2 Unintended pregnancy ‐ individually‐randomi sed trials .

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 3 Unintended pregnancy ‐ cluster‐adjusted + individual .
Figuras y tablas -
Analysis 2.3

Comparison 2 Sensitivity analysis [Multiple interventions]: Unintended pregnancy, Outcome 3 Unintended pregnancy ‐ cluster‐adjusted + individual .

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 1 Initiation of sexual intercourse ‐ individually RCT.
Figuras y tablas -
Analysis 3.1

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 1 Initiation of sexual intercourse ‐ individually RCT.

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.
Figuras y tablas -
Analysis 3.2

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual.
Figuras y tablas -
Analysis 3.3

Comparison 3 Sensitivity analysis [Multiple interventions]: Initiation of intercourse, Outcome 3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual.

Comparison 4 Educational interventions , Outcome 1 Initiation of sexual intercourse ‐ cluster RCT.
Figuras y tablas -
Analysis 4.1

Comparison 4 Educational interventions , Outcome 1 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 4 Educational interventions , Outcome 2 Use of birth control methods ‐ cluster RCT.
Figuras y tablas -
Analysis 4.2

Comparison 4 Educational interventions , Outcome 2 Use of birth control methods ‐ cluster RCT.

Comparison 4 Educational interventions , Outcome 3 Use of contraceptives ‐ individually RCT.
Figuras y tablas -
Analysis 4.3

Comparison 4 Educational interventions , Outcome 3 Use of contraceptives ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 1 Unintended pregnancy ‐ individually RCT.
Figuras y tablas -
Analysis 5.1

Comparison 5 Contraceptive‐promoting interventions, Outcome 1 Unintended pregnancy ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.
Figuras y tablas -
Analysis 5.2

Comparison 5 Contraceptive‐promoting interventions, Outcome 2 Initiation of sexual intercourse ‐ cluster RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 3 Use of birth control methods ‐ cluster RCT.
Figuras y tablas -
Analysis 5.3

Comparison 5 Contraceptive‐promoting interventions, Outcome 3 Use of birth control methods ‐ cluster RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 4 Use of birth control methods ‐ individually RCT.
Figuras y tablas -
Analysis 5.4

Comparison 5 Contraceptive‐promoting interventions, Outcome 4 Use of birth control methods ‐ individually RCT.

Comparison 5 Contraceptive‐promoting interventions, Outcome 5 Sexually Transmitted Diseases ‐ individually RCT.
Figuras y tablas -
Analysis 5.5

Comparison 5 Contraceptive‐promoting interventions, Outcome 5 Sexually Transmitted Diseases ‐ individually RCT.

Contraceptive‐promoting interventions (individual RCTs)

Patient or population: Male and female adolescents aged 10 years to 19 years
Setting: All settings
Intervention: Contraceptive‐ promoting interventions
Comparison: No additional activity/intervention to existing conventional population‐wide activities

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Quality of the evidence
(GRADE)

Risk with No intervention/standard curriculum

Risk with Contraception Intervention

Unintended pregnancy
follow up: range 6 months to 12 months

Study population

RR 1.01
(0.81 to 1.26)

3440
(2 RCTs)

⊕⊕⊕⊝
MODERATE 1

83 per 1000

84 per 1000
(67 to 105)

Moderate

85 per 1000

86 per 1000
(69 to 107)

Use of birth control methods (condom use in last sex)
follow up: range 6 months to 12 months

Study population

RR 0.95
(0.87 to 1.04)

3091
(2 RCTs)

⊕⊕⊕⊕
HIGH

367 per 1000

348 per 1000
(319 to 381)

Moderate

312 per 1000

296 per 1000
(271 to 324)

Use of birth control methods (hormonal contraceptives)
follow up: range 6 months to 12 months

Study population

RR 2.22
(1.07 to 4.62)

3091
(2 RCTs)

⊕⊕⊕⊕
HIGH

165 per 1000

365 per 1000
(176 to 760)

Moderate

131 per 1000

292 per 1000
(141 to 607)

Sexually Transmitted Diseases
follow up: range 6 months to 12 months

Study population

RR 0.92
(0.75 to 1.13)

3440
(2 RCTs)

⊕⊕⊕⊕
HIGH

103 per 1000

95 per 1000
(77 to 117)

Moderate

98 per 1000

90 per 1000
(73 to 111)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

1 Downgraded by 1 for imprecision: confidence interval fail to appreciable harm and included the null value

Figuras y tablas -

Educational interventions (cluster RCTs)

Patient or population: Male and female adolescents aged 10 years to 19 years
Setting: All settings
Intervention: Educational interventions
Comparison: No additional activity/intervention to existing conventional population‐wide activities

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Quality of the evidence
(GRADE)

Risk with No intervention/Standard curriculum

Risk with Educational intervention

Use of birth control methods (condom use at last sex)
follow up: range 5 months to 24 months

Study population

RR 1.18
(1.06 to 1.32)

1431
(2 RCTs)

⊕⊕⊕⊝
MODERATE 1

261 per 1000

308 per 1000
(277 to 345)

Moderate

534 per 1000

630 per 1000
(566 to 704)

Initiation of sexual intercourse (mixed gender)
follow up: range 12 months to 24 months

Study population

RR 0.95
(0.71 to 1.27)

672
(2 RCTs)

⊕⊕⊝⊝
LOW 1 2

227 per 1000

215 per 1000
(161 to 288)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

1 Several risk of bias assessment were unclear (not provided in the text)

2 Low number of events and confidence interval includes the null value

Figuras y tablas -

Multiple interventions (cluster RCTs)

Patient or population: Male and female adolescents aged 10 years to 19 years
Setting: All settings
Intervention: Multiple interventions
Comparison: No additional activity/intervention to existing conventional population‐wide activities

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Quality of the evidence
(GRADE)

Risk with No Intervention/Standard curriculum

Risk with Multiple interventions

Unintended pregnancy
follow up: range 3 months to 48 months

Study population

RR 0.50
(0.23 to 1.09)

3149
(5 RCTs)

⊕⊕⊝⊝
LOW 1 2 3

67 per 1000

33 per 1000
(15 to 73)

Moderate

25 per 1000

13 per 1000
(6 to 27)

Initiation of sexual intercourse (mixed gender)
follow up: range 3 months to 36 months

Study population

RR 0.84
(0.68 to 1.04)

8608
(7 RCTs)

⊕⊝⊝⊝
VERY LOW 1 4 5

253 per 1000

212 per 1000
(172 to 263)

Moderate

212 per 1000

178 per 1000
(144 to 220)

Use of birth control methods (condom use at last sex)
follow up: range 6 months to 17 months

Study population

RR 1.01
(0.93 to 1.09)

2620
(4 RCTs)

⊕⊕⊕⊝
MODERATE 1 6

585 per 1000

591 per 1000
(544 to 637)

Moderate

565 per 1000

570 per 1000
(525 to 615)

Use of birth control methods (consistent condom use)
follow up: range 6 months to 36 months

Study population

RR 1.95
(0.70 to 5.44)

826
(3 RCTs)

⊕⊕⊝⊝
LOW 1 7

353 per 1000

689 per 1000
(247 to 1000)

Moderate

133 per 1000

259 per 1000
(93 to 722)

Use of birth control methods (hormonal contraceptives)
follow up: range 16 months to 24 months

Study population

RR 1.01
(0.72 to 1.43)

3987
(3 RCTs)

⊕⊝⊝⊝
VERY LOW 1 5 7

244 per 1000

246 per 1000
(176 to 349)

Moderate

251 per 1000

254 per 1000
(181 to 360)

Sexually Transmitted Diseases
follow up: range 6 months to 17 months

Study population

RR 0.76
(0.27 to 2.14)

420
(2 RCTs)

⊕⊕⊝⊝
LOW 1 8

37 per 1000

28 per 1000
(10 to 80)

Moderate

31 per 1000

24 per 1000
(8 to 66)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

1 Downgraded by 1 for risk of bias; several assessments were unclear due to no information provided. Such potential limitations are likely to lower confidence in the estimate of effect

2 Downgraded by 1 for imprecision; low number of events, confidence interval includes appreciable benefit and null value

3 Heterogeneity could be explained (difference in comparison intervention and length of follow up)

4 Downgraded by 1 for imprecision: confidence interval includes appreciable benefit

5 Downgraded by 1 for inconsistency: unexplained large variations in effect

6 Confidence interval includes the null value, however, the sample size and number of events are fairly large and confidence interval is relatively narrow

7 Downgraded by 1 for imprecision: confidence interval includes appreciable benefit and harm

8 Downgraded by 1 for imprecision; low number of events, confidence interval includes appreciable benefit and harm

Figuras y tablas -

Multiple interventions ( individual RCTs)

Patient or population: Male and female adolescents aged 10 years to 9 years
Setting: All settings
Intervention: Multiple interventions
Comparison: No additional activity/intervention to existing conventional population‐wide activities

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Quality of the evidence
(GRADE)

Risk with No Intervention/Standard curriculum

Risk with Multiple interventions

Unintended pregnancy
follow up: range 12 months to 36 months

Study population

RR 0.66
(0.50 to 0.87)

1905
(4 RCTs)

⊕⊕⊕⊝
MODERATE 1

116 per 1000

76 per 1000
(58 to 101)

Moderate

149 per 1000

98 per 1000
(74 to 129)

Initiation of sexual intercourse (mixed gender)
follow up: range 9 months to 36 months

Study population

RR 0.99
(0.74 to 1.32)

1796
(4 RCTs)

⊕⊕⊕⊝
MODERATE 1

410 per 1000

406 per 1000
(304 to 542)

Moderate

236 per 1000

234 per 1000
(175 to 312)

Use of birth control methods (condom use in last sex)
follow up: range 12 months to 24 months

Study population

RR 1.00
(0.95 to 1.06)

796
(3 RCTs)

⊕⊕⊕⊝
MODERATE 1 6

840 per 1000

840 per 1000
(798 to 891)

Moderate

837 per 1000

837 per 1000
(795 to 887)

Use of birth control methods (consistent condom use)
follow up: range 12 months to 24 months

Study population

RR 1.21
(0.95 to 1.54)

1681
(5 RCTs)

⊕⊕⊝⊝
LOW 1 5 6

353 per 1000

427 per 1000
(335 to 544)

Moderate

476 per 1000

575 per 1000
(452 to 732)

Sexually Transmitted

Diseases
follow up: mean 12 months

Study population

RR 0.89
(0.65 to 1.22)

699
(2 RCTs)

⊕⊝⊝⊝
VERY LOW 1 5 8

191 per 1000

170 per 1000
(124 to 233)

Moderate

270 per 1000

241 per 1000
(176 to 330)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

1 Downgraded by 1 for risk of bias; several assessments were unclear due to no information provided. Such potential limitations are likely to lower confidence in the estimate of effect

2 Downgraded by 1 for imprecision; low number of events, confidence interval includes appreciable benefit and null value

3 Heterogeneity could be explained (difference in comparison intervention and length of follow up)

4 Downgraded by 1 for imprecision: confidence interval includes appreciable benefit

5 Downgraded by 1 for inconsistency: unexplained large variations in effect

6 Confidence interval includes the null value, however, the sample size and number of events are fairly large and confidence interval is relatively narrow

7 Downgraded by 1 for imprecision: confidence interval includes appreciable benefit and harm

8 Downgraded by 1 for imprecision; low number of events, confidence interval includes appreciable benefit and harm

Figuras y tablas -
Table 1. Studies that Could not be included in meta‐analysis

Intervention

Outcome

Study ID

Number Assessed

Case affected

Control affected

Test Statistics

95% CI

p‐value

Educational intervention

Pregnancy

Mitchell‐DiCenso 1997

1701

OR: 0.97

0.93 to 1.0

0.04

Initiation of intercourse

Clark 2005

156

Beta: 1.604 and SE: 1.00

< 0.11

Aarons 2000 (females)

139

Adj. OR: 1.88

1.02 to 3.47

0.04

Aarons 2000 (males)

123

Adj. OR: 1.18

0.61 to 2.29

0.62

Perskin 2015

1079

OR: 1.00

0.70 to 1.41

Changes in knowledge and attitudes about the risk of unintended pregnancy

Blake 2001

351

92.9%

91.8%

ns

Use of birth control at last sex

Mitchell‐DiCenso 1997 (females)

109

42.2%

46.7%

OR: 1.03

1.00 to 1.07

0.03

Mitchell‐DiCenso 1997 (males)

214

39.3%

35.9%

OR: 1.06

1.02 to 1.77

0.005

Aarons 2000 (females)

135

Adj. OR: 3.39

1.16 to 9.95

0.025

Aarons 2000 (males)

125

Adj. OR: 1.53

0.55 yo 4.26

0.42

Use of condom at last sex

Okonofua 2003

1896

39.1%

31.9%

OR: 1.41

1.12 to 1.77

Clark 2005

221

77%

73%

Unprotected intercourse in the past 3 monthsa

Kogan 2012

502

Beta: ‐0.375 and SE: 0.32

>0.05

Ever had sex without condoms

Dilorio 2007

Mean: 0.23

Mean: 0.57

‐0.61 to ‐0.06

0.03

Multiple interventions

Pregnancy

Coyle 2006

308

OR; 0.84

0.61

Diclemente 2004

460

OR: 0.53

0.27 to 1.03

0.06

Stephenson 2004b

1172

2.3%

3.3%

0.07

Kirby 2004

2145

OR: 1.34

0.98 to 1.84

0.07

Coyle 2006

417

OR: 0.77

0.49 to 1.23

0.28

Smith 1994

95

< 0.05

O'Donnell 2002

195

6.8%

18.5%

Morrison‐Beedy 2013

323

B=‐.823

OR: 0.44

0.009

Allen 1997

560

OR: 0.41

Initiation of sexual intercourse (mixed gender)

Coyle 2006

94

OR: 1.23

0.51 to 2.97

0.65

Smith 1994

95

.Mean: 1.19

.Mean: 2.74

Basen‐Engquist 2001

8326

OR: 1.03

0.88 to 1.21

0.69

Markham 2012

627

AOR:0.65

0.54,0.77

<.01

O'Donnell 2002

195

40.1%

66.1%

OR: 0.39

0.20 to 0.76

0.005

Markham 2012

735

AOR:0.82

0.51,1.34

>0.05

Coyle 1999

2565

OR:1.13

SE: 0.24

0.71 to 1.82

0.60

Initiation of sexual intercourse (male)

Coyle 2004

1412

19.3%

27.7%

model R2: 0.118

0.02

Kirby 2004

809

OR: 1.08

0.80 to 1.46

0.63

Stephenson 2004

8156

32.7%

31.1%

OR: 0.90

0.65 to 1.23

0.35

Eisen 1990

408

36%

44%

Initiation of sexual intercourse (female)

Coyle 2004

1417

20.3%

22.1%

model R2: 0.145

0.53

Kirby 2004

1220

OR: 0.88

0.59 to 1.31

0.54

Stephenson 2004

8156

34.7%

40.8%

OR: 0.80

0.66 to 0.97

0.008

Eisen 1990

480

27%

22%

Use of condoms at last sex

Kirby 2004

2145

OR: 1.38

1.06 to 1.79

0.02

Coyle 2006

359

OR: 1.00

0.49 to 1.23

0.99

Diclemente 2004

460

OR: 3.94

2.58 to 6.03

< .001

Downs 2004

258

OR: 2.13

0.15

Norton 2012

198

OR: 0.93

‐0.75,0.62

0.85

Coyle 1999

1018

OR:191

SE:0.27

1.13 to 3.21

0.02

Childbirth

Henderson 2007

4196

300/1000

274/1000

OR: 14.6

0.32

Abortion

Henderson 2007

4196

127/1000

112/1000

OR: 26.4

0.40

Consistent condom use at 12 months

Sieving 2011

253

Mean: 0.96 (116/126)

Mean: 0.66 (81/127)

ARR:145

1.26 to 1.67

0.00

Consistent condom use at 24 months

Sieving 2011

204

Mean:1.53

Mean: 0.93

ARR: 1.57

1.28,1.94

Consistent hormonal contraceptive use at 12 months

Sieving 2011

253

Mean: 4.27 (74/126)

Mean: 2.91 (51/127)

ARR:1.46

1.13 to 1.89

0.00

Consistent hormonal contraceptive use at 24 months

Sieving 2011

203

Mean: 3.29

Mean: 2.34

ARR: 1.30

1.06,1.58

Minnis 2014

162

OR:0.42

0.12

Use of condoms at first sex

Coyle 1999

285

OR:0.68

SE:0.48

0.26 to 1.75

0.42

Protected against pregnancy at last sex

Coyle 1999

998

OR:1.62

SE:0.22

1.05 to 2.50

0.03

Sexually Transmitted Infections

Morrison‐Beedy 2013

323

B=‐0.067

OR: ‐0.94

0.77

Jemmott 2005c

Mean:10.5

SE: 2.9

Mean:18.2

SE:2.8

0.05

Baird 2010: The following listed outcomes were reported. However, the method of reporting made difficult to extract correct estimates.

1. Pregnancy School girls and dropouts among the treatment group are 1.1 percentage points less likely to have become pregnant over the past year. Not statistically significant.

2. Onset of sexual intercourse There was a 46.6% reduction in the onset of sexual activity among initial dropouts (P < 0.01) and a 31.3% reduction in the onset of sexual activity among initial schoolgirls (P = 0.112).

3.Condom use The intervention had no impact on self‐reported condom use.

a ‐ Binary outcome (did unprotected intercourse occur or not?)

b ‐ Study (Stephenson 2008) same as Stephenson 2004, but with an extended follow up (7yrs)

c ‐ Data comparing skills‐based intervention versus health‐promotion intervention

Analyses assessing impact on delay of sexual initiation excluded individuals who reported any type of sexual intercourse at baseline

Analyses assessing impact on other on sexual behaviours are limited to individuals that are sexually active

ns ‐ non‐significant

Figuras y tablas -
Table 1. Studies that Could not be included in meta‐analysis
Comparison 1. Multiple interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy [individually randomised trials] Show forest plot

4

1905

Risk Ratio (M‐H, Fixed, 95% CI)

0.66 [0.50, 0.87]

2 Unintended pregnancy [cluster‐randomised trials] Show forest plot

5

3149

Risk Ratio (M‐H, Random, 95% CI)

0.50 [0.23, 1.09]

3 Initiation of sexual intercourse ‐ individually RCT Show forest plot

4

1796

Risk Ratio (M‐H, Random, 95% CI)

0.99 [0.74, 1.32]

4 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

7

8608

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.68, 1.04]

5 Use of birth control methods ‐ individually RCT Show forest plot

8

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 Condom use in last sex

3

796

Risk Ratio (M‐H, Random, 95% CI)

1.00 [0.95, 1.06]

5.2 Consistent condom use

5

1681

Risk Ratio (M‐H, Random, 95% CI)

1.21 [0.95, 1.54]

5.3 Contraceptive use at last sex

1

408

Risk Ratio (M‐H, Random, 95% CI)

0.99 [0.95, 1.03]

5.4 Consistent contraceptive use

1

253

Risk Ratio (M‐H, Random, 95% CI)

1.29 [1.06, 1.59]

6 Use of birth control methods ‐ cluster RCT Show forest plot

6

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

6.1 Condom use at last sex

4

2620

Risk Ratio (M‐H, Random, 95% CI)

1.01 [0.93, 1.09]

6.2 Consistent condom use

3

826

Risk Ratio (M‐H, Random, 95% CI)

1.95 [0.70, 5.44]

6.3 Hormonal contraceptives

3

3987

Risk Ratio (M‐H, Random, 95% CI)

1.01 [0.72, 1.43]

7 Sexually Transmitted Diseases ‐ individually RCT Show forest plot

2

699

Risk Ratio (M‐H, Fixed, 95% CI)

0.89 [0.65, 1.22]

8 Sexually Transmitted Diseases ‐ cluster RCT Show forest plot

2

420

Risk Ratio (M‐H, Fixed, 95% CI)

0.76 [0.27, 2.14]

9 Childbirth ‐ cluster RCT Show forest plot

1

4776

Odds Ratio (M‐H, Fixed, 95% CI)

0.64 [0.52, 0.79]

10 Childbirth ‐ individually RCT Show forest plot

1

484

Risk Ratio (M‐H, Fixed, 95% CI)

0.67 [0.31, 1.45]

11 Second unintended pregnancy ‐ individually RCT Show forest plot

1

149

Risk Ratio (M‐H, Fixed, 95% CI)

0.48 [0.22, 1.02]

12 Abortion (cluster RCT) Show forest plot

1

4776

Odds Ratio (M‐H, Fixed, 95% CI)

0.93 [0.72, 1.21]

Figuras y tablas -
Comparison 1. Multiple interventions
Comparison 2. Sensitivity analysis [Multiple interventions]: Unintended pregnancy

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy ‐ cluster‐randomi sed trials Show forest plot

2

497

Risk Ratio (M‐H, Random, 95% CI)

0.20 [0.10, 0.39]

2 Unintended pregnancy ‐ individually‐randomi sed trials Show forest plot

3

1421

Odds Ratio (M‐H, Fixed, 95% CI)

0.68 [0.46, 1.00]

3 Unintended pregnancy ‐ cluster‐adjusted + individual Show forest plot

5

1918

Risk Ratio (M‐H, Fixed, 95% CI)

0.53 [0.39, 0.72]

Figuras y tablas -
Comparison 2. Sensitivity analysis [Multiple interventions]: Unintended pregnancy
Comparison 3. Sensitivity analysis [Multiple interventions]: Initiation of intercourse

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Initiation of sexual intercourse ‐ individually RCT Show forest plot

3

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 Gender mixed or not specified

3

1312

Risk Ratio (M‐H, Random, 95% CI)

1.18 [0.67, 2.09]

2 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

4

1687

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.57, 1.25]

2.1 Gender mixed or not specified

4

1687

Risk Ratio (M‐H, Random, 95% CI)

0.84 [0.57, 1.25]

3 Initiation of sexual intercourse ‐ cluster‐adjusted + individual Show forest plot

7

2999

Odds Ratio (M‐H, Fixed, 95% CI)

0.88 [0.74, 1.05]

3.1 Gender mixed or not specified

7

2999

Odds Ratio (M‐H, Fixed, 95% CI)

0.88 [0.74, 1.05]

Figuras y tablas -
Comparison 3. Sensitivity analysis [Multiple interventions]: Initiation of intercourse
Comparison 4. Educational interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

2

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

1.1 Gender mixed or not specified

2

672

Risk Ratio (M‐H, Fixed, 95% CI)

0.95 [0.71, 1.27]

2 Use of birth control methods ‐ cluster RCT Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 condom use at last sex

2

1431

Risk Ratio (M‐H, Random, 95% CI)

1.18 [1.06, 1.32]

3 Use of contraceptives ‐ individually RCT Show forest plot

1

360

Risk Ratio (M‐H, Fixed, 95% CI)

2.5 [1.39, 4.48]

Figuras y tablas -
Comparison 4. Educational interventions
Comparison 5. Contraceptive‐promoting interventions

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Unintended pregnancy ‐ individually RCT Show forest plot

2

3440

Risk Ratio (M‐H, Fixed, 95% CI)

1.01 [0.81, 1.26]

2 Initiation of sexual intercourse ‐ cluster RCT Show forest plot

1

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

2.1 Female

1

1446

Risk Ratio (M‐H, Fixed, 95% CI)

0.89 [0.76, 1.04]

2.2 Male

1

1560

Risk Ratio (M‐H, Fixed, 95% CI)

1.02 [0.87, 1.21]

3 Use of birth control methods ‐ cluster RCT Show forest plot

1

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

3.1 Hormonal contraceptives

1

415

Risk Ratio (M‐H, Fixed, 95% CI)

0.90 [0.69, 1.18]

4 Use of birth control methods ‐ individually RCT Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

4.1 Condom use in last sex

2

3091

Risk Ratio (M‐H, Random, 95% CI)

0.95 [0.87, 1.04]

4.2 Consistent condom use

1

1950

Risk Ratio (M‐H, Random, 95% CI)

0.90 [0.71, 1.15]

4.3 Hormonal contraceptives

2

3091

Risk Ratio (M‐H, Random, 95% CI)

2.22 [1.07, 4.62]

5 Sexually Transmitted Diseases ‐ individually RCT Show forest plot

2

3440

Risk Ratio (M‐H, Fixed, 95% CI)

0.92 [0.75, 1.13]

Figuras y tablas -
Comparison 5. Contraceptive‐promoting interventions