Level of evidence and criteria

Resilience factors

Level 1: strong evidence (SRs and MAs)

• Factor has been studied with regard to its association to resilience (i.e. mental health or well‐being or psychological adaptation despite (acute or chronic) stressors, life events or traumas) in observational (cross‐sectional or longitudinal) studies in adults

• There is evidence from SRs AND MAs

Level 1a: there is evidence for this factor from several SRs AND several MAs (both across different populations)

• Active coping (e.g. problem‐solving, planning)

  • 2 MAs: Kvillemo 2014; Moskowitz 2009

  • 4 SRs: Bjørkløf 2013; Kneebone 2003; Senra 2015; Van Kessel 2013

  • Cross‐sectional studies: e.g. Al‐Yagon 2009; Dörfel 2008; Lechner 2007; Luo 2015; Marty 2010; Wang 2014

  • Longitudinal studies: e.g. Butler 2009; Silver 2002

• Self‐efficacy

  • 2 MAs: Jackson 2014; Lee 2013

  • 9 SRs: Allart 2013; Dias 2015; Korpershoek 2011; Luszczynska 2009; Morris 2013; Peter 2012; Stewart 2011; Van Kessel 2013; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Barry 2003; Northouse 2002; Orengo 2001; Schwarzer 2008; Wright 2008

  • Longitudinal studies: e.g. DeRoon‐Cassini 2010; Guest 2015; Hartley 2008

• Optimism or positive attributional style

  • 4 MAs: Helgeson 2006; Lee 2013; Prati 2009; Shand 2015

  • 5 SRs: Dias 2015; Duits 1997; Peter 2012; Stewart 2011; Van Kessel 2013

  • Cross‐sectional studies: e.g. Martin‐Krumm 2003; Sumer 2005

  • Longitudinal studies: e.g. Ahmad 2010; Carver 2010; Fresco 2006; Grote 2007; Kivimäki 2005; Myhren 2010; Segovia 2012

• Social support

  • 4 MAs: Lee 2013; Ozer 2003; Prati 2009; Shand 2015

  • 11 SRs: Allart 2013; Casale 2013; Dias 2015; Duits 1997; McCann 2013; Morris 2013; Paterson 2013; Pragodpol 2013; Senra 2015; Stewart 2011; Van Kessel 2013

  • Cross‐sectional studies: e.g. Ahern 2004; Fuller‐Iglesias 2008; Kaspersen 2003; Schumm 2006

  • Longitudinal studies: e.g. Bartone 1989; Dyrbye 2010; Johnson 2009; Koenen 2003; Solomon 1988

• Cognitive flexibility (e.g. positive reappraisal, acceptance of negative situations and emotions)¹

  • 6 MAs: Helgeson 2006; Kvillemo 2014; McIntosh 2012; Moskowitz 2009; Prati 2009; Shand 2015

  • 11 SRs: Allart 2013; Bjørkløf 2013; Dias 2015; Guardino 2013; Kneebone 2003; Morris 2013; Nowlan 2015; Peter 2012; Senra 2015; Stewart 2011; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Bailey 2013; Farber 2003; Johnson 2015; Min 2013

  • Longitudinal studies: e.g. Park 2008; Silver 2002; Wade 2001

• Religiosity or spirituality or religious coping (e.g. frequent religious attendance)¹

  • 7 MAs: Ano 2005; Helgeson 2006; McIntosh 2012; Moskowitz 2009; Prati 2009; Salsman 2015; Shand 2015

  • 7 SRs: Bjørkløf 2013; Guardino 2013; McCann 2013; Peter 2012; Senra 2015; Stewart 2011; Visser 2010

  • Cross‐sectional studies: e.g. Cruz 2016; Tsai 2015

  • Longitudinal studies: e.g. Hebert 2007; Kasen 2014; Koenig 2007; Walsh 2002

Level 1b: there is evidence for this factor from several SRs AND a single MA (both across different populations)

• Positive emotions or positive affect

  • 1 MA: Lee 2013

  • 2 SRs: Van Kessel 2013; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Cohen 2006; Gloria 2016; Ong 2006

  • Longitudinal studies: e.g. Fredrickson 2003; Geschwind 2010; Quale 2010; Strand 2006; Zautra 2005

• Hardiness

  • 1 MA: Eschleman 2010

  • 4 SRs: Brooks 2003; Dias 2015; McCann 2013; Stewart 2011

  • Cross‐sectional studies: e.g. Alexander 2001; Andrew 2008; Bernas 2000; Farber 2000; Hystad 2011; Judkins 2005; King 1998; Natvik 2011; Waysman 2001; Weiss 2002

  • Longitudinal studies: e.g. Dolan 2006; Bartone 1989

• Self‐esteem

  • 1 MA: Lee 2013

  • 4 SRs: Allart 2013; Peter 2012; Stewart 2011; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Besser 2014; Fernández‐Lansac 2012; Hayter 2014

  • Longitudinal studies: e.g. Bookwala 2014

Level 1c: there is evidence for this factor from several SRs (across different populations) AND a single MA (in the same population)

• Meaning in life or purpose in life

  • 1 MA: Winger 2016

  • 5 SRs: Allart 2013; Peter 2012; Van Kessel 2013; Van Leeuwen 2012; Visser 2010)

  • Cross‐sectional studies: e.g. Alim 2008; Bauer‐Wu 2005; Blackburn 2015; Feder 2013; Lyon 2001; Owens 2009; Pietrzak 2013; Schaefer 2013; Smith 2009; Tsai 2015

  • Longitudinal studies: e.g. Krause 2007; Tsai 2016

• Sense of coherence

  • 1 MA: Winger 2016

  • 7 SRs: Allart 2013; Bjørkløf 2013; Eriksson 2006; Peter 2012; Pragodpol 2013; Van Kessel 2013; Van Leeuwen 2012)

  • Cross‐sectional studies: e.g. Al‐Yagon 2009; Cohen 2003; Forstmeier 2009

  • Longitudinal studies: e.g. Frommberger 1999; Schnyder 2008

Level 2: moderate evidence (only SRs or single MA)

• Factor has been studied with regard to its association to resilience (i.e. mental health or well‐being or psychological adaptation despite (acute or chronic) stressors, life events or traumas) in observational (cross‐sectional or longitudinal) studies in adults

• There is evidence from SR OR a single MA

Level 2a: there is evidence for this factor from several SRs (across different populations) OR there is no evidence from SRs, but from a MA (across different populations)

• (Internal) Locus of control

  • 6 SRs: Bjørkløf 2013; Dias 2015; Saksvik 2011; Senra 2015; Stewart 2011; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Kilic 2013; Sattler 2014; Solomon 1988

  • Longitudinal studies: e.g. Karstoft 2015; Lawler 1992; Milte 2015; White 2012

• Coping flexibility

  • 1 MA: Cheng 2014

  • Cross‐sectional studies: e.g. Atal 2016; Bonanno 2011; Burton 2012; Park 2015

  • Longitudinal studies: e.g. Bonanno 2004; Galatzer‐Levy 2012

Level 2b: there is evidence for this factor from several SRs (in the same population)

• Hope

  • 2 SRs: Peter 2012; Van Leeuwen 2012

  • Cross‐sectional studies: e.g. Besser 2014; Hernandez 2013; Ong 2006; Truitt 2012

  • Longitudinal studies: e.g. Ho 2010

Level 2c: there is evidence for this factor from a single SR (in the same population)

• Humour

  • 1 SR: McCann 2013

  • Cross‐sectional studies: e.g. Abel 2002a; Abel 2002b

  • Longitudinal studies: e.g. Kuiper 1992; Nezu 1988

Level 3: weak evidence (no SR or MA)

• Expert opinion without explicit critical appraisal

• Factor has not been studied sufficiently with regard to its association to resilience (i.e. mental health or well‐being or psychological adaptation despite (acute or chronic) stressors, life events or traumas) in adults

• Factor is only mentioned in unsystematic narrative reviews or discussion papers, or both

• Altruism

  • Narrative reviews or discussion papers: Haglund 2007; Southwick 2005; Wu 2013

Evidence‐based resilience factor

Examples of training methods to address the resilience factor

Meaning in life or purpose in life

Introduce the benefits of purpose in life; support individuals in identifying important sources of meaning (e.g. social relationships, work) as well as in setting priorities and guiding values for their life (e.g. Sood 2011)

Sense of coherence (comprehensibility, meaningfulness, manageability)

Promote the understanding of external life challenges, personal beliefs and emotions; encourage participants to reflect on personal (internal or external) resources and to use them more frequently (e.g. Tan 2016)

Positive emotions or positive affect

Psychoeducation on emotions; mindfulness techniques; support individuals in identifying pleasant activities to enhance positive emotions (e.g. Jennings 2013)

Hardiness (challenge, commitment, control)

Situational reconstruction (i.e. imagination of stressful circumstances); focusing (i.e. reflection on bodily sensations of emotional upset) (e.g. Maddi 1998; Maddi 2009)

Self‐esteem

Support participants in identifying personal strengths

Active coping (e.g. problem‐solving, planning)

Introduce the problem‐solving model and familiarise participants with the use of active coping strategies in stressful situations (e.g. making action plans) (e.g. Abbott 2009; Bekki 2013; Sahler 2013)

Self‐efficacy

Support participants in identifying personal strengths and other sources of self‐efficacy (e.g. social connections); support individuals in realising previous successes (e.g. coping of negative situations)

Optimism or positive attributional style

Teach participants to adapt a more positive attributional style for stressful (i.e. external, unstable, specific) and pleasant events (i.e. internal, stable, global); encourage individuals to gain a brighter outlook for the future by enhancing their attention for and the discovery of positive aspects in their lives (e.g. Carver 2010; Sadow 1993)

Social support

Encourage the individual’s reflection on his or her current network (i.e. magnitude of social network, positive or negative aspects in social relationships); enhance the individual’s support network by providing them with communication techniques (e.g. Kent 2011; Schachman 2004; Sood 2011; Steinhardt 2008)

Cognitive flexibility (e.g. positive reappraisal, acceptance of negative situations and emotions)

Positive reappraisal: introduction of ABC (Activating Event, Belief, Consequence) Technique of Irrational Beliefs (Ellis 1957) of cognitive therapy; train participants in identifying and challenging maladaptive thoughts and replacing them by more positive ones (e.g. Abbott 2009; Farchi 2010; Songprakun 2012; Steinhardt 2008)

Acceptance: relaxation or mindfulness techniques

Religiosity or spirituality or religious coping (e.g. frequent religious attendance)

Spiritual exercises like meditation or yoga; psychoeducation on coping strategies like regular praying or participating in religious community activities (e.g. worship) (e.g. Sood 2011)

N°

Measure

Theory and item selection

Internal consistency

Validity

Rating

1

Resilience Scale (RS‐25)

(Wagnild 1993)⁴

+

+++

+++

6✦

2

Brief Resilience Scale (BRS)

(Smith 2008)

+

+++

+++

6✦

3

Ego Resiliency

(Klohnen 1996)⁴

+

++

+++

5✦

4

Connor ‐ Davidson Resilience Scale (CD‐RISC)

(Connor 2003)

+

++

+++

5✦

5

Resilience Scale for Adults (RSA₃₃)

(Friborg 2005)

+

++

+++

5✦

6

Trauma Resilience Scale (TRS₃₇)

(Madsen 2010)

+

+++

++

5✦

7

Ego ‐ Resiliency Scale (ER89)

(Block 1996)⁴

‐

++

+++

5✧

8

Resilience Scale (RS‐14)

(Wagnild 2010)⁴

+

+++

+

4✦

9

Resilience Scale for Adults (RSA₃₇)

(Friborg 2003)

+

++

++

4✦

10

Resilience at Work Scale

(Winwood 2013)

+

++

++

4✦

11

Workplace Resilience Inventory (WRI)

(McLarnon 2013)

+

++

++

4✦

12

Multidimensional Trauma Recovery and Resiliency Scale (MTRR)

(Harvey 2003)

+

+++

+

4✦

13

Resiliency Attitudes and Skills Profile (RASP)

(Hurtes 2001)

+

+++

+

4✦

14

Resilience Appraisals Scale (RAS)

(Johnson 2010)

‐

+++

+

4✧

15

Revised Ego Resiliency 89 Scale (ER89‐R)

(Alessandri 2007)⁴

+

++

+

3✦

16

Ego Resiliency

(Bromley 2006)⁴

+

++

+

3✦

17

Connor ‐ Davidson Resilience Scale (CD‐RISC‐10)

(Campbell‐Sills 2007)

+

++

+

3✦

18

Resilience Scale for Adults (RSA₄₅)

(Hjemdal 2001)

+

+++

‐

3✦

19

Brief Resilient Coping Scale (BRCS)

(Sinclair 2004)

+

+

++

3✦

20

Trauma Resilience Scale (TRS₄₈)

(Madsen 2010)

+

+++

‐

3✦

21

Child and Youth Resilience Measure ‐ 28 (CYRM‐28)

(Liebenberg 2012; Ungar 2008)

+

+++

‐

3✦

22

Post‐traumatic Growth Inventory (PTGI)

(Tedeschi 1996)⁵

+

++

+

3✦

23

Adolescent Resilience Scale

(Oshio 2002; Oshio 2003)

‐

++

+

3✧

24

Resilience and Reintegration (20 items drawn from Spirit Core Scale)

(Waite 2004)

‐

+++

‐

3✧

25

Psychological resilience

(Windle 2008)

+

++

‐

2✦

26

Child and Youth Resilience Measure ‐ 12 (CYRM‐12)

(Liebenberg 2013)

+

++

‐

2✦

27

Resilience scale

(Bekki 2013)

+

++

‐

2✦

28

Perceived resilience

(Van der Kleij 2011)

‐

++

‐

2✧

29

Romanian Scale of Resilience to Occupational Stress (SROS)

(Aniţei 2012)

‐

‐

‐

0✧

Source

• Study ID (created by review author)

• Report ID (created by review author)

• Review author ID (created by review author)

• Citation and contact detail

Eligibility

• Confirm eligibility for review

• Reason for exclusion

Methods

• Study design

• Total study duration

• Sequence generation*

• Allocation sequence concealment*

• Blinding*

• Other concerns about bias:*

  • analyses to assure baseline comparability of groups for sociodemographic characteristics and outcomes of interest; and

  • selection of comparison group

Participants

• Total number

• Setting

• Diagnostic criteria

• Age

• Sex

• Country

• Comorbidity

• Sociodemographics

• Date of study

Interventions

• Total number of intervention groups

• For each intervention and comparison group of interest:

  • specific intervention; and

  • intervention details (sufficient for replication, if feasible)

Outcomes

• Outcomes and time points (1) collected; (2) reported*

• For each outcome of interest:

  • outcome definition (with diagnostic criteria, if relevant)

  • unit of measurement (if relevant)

• For scales: upper and lower limits and whether high or low score is good

Results

• Number of participants allocated to each intervention group

• For each outcome of interest:

  • sample size

  • missing participants*

  • summary data for each intervention group (e.g. means and SDs for continuous data at baseline and any time point after treatment; change);

  • estimate of effect with standard error, 95% CI and P value

  • subgroup analyses

• Potential adverse effects

Miscellaneous aspects

• Funding source

• Declaration of interests for the primary investigators

• Key conclusions of the study authors

• Miscellaneous comments from the study authors

• References to other relevant studies

• Correspondence required

• Miscellaneous outcomes by the review authors

Item

Judgment

Description

1. Random sequence generation (selection bias). We will describe the method used to generate the allocation sequence in sufficient detail for each included trial to allow an assessment of whether it should produce comparable groups.

Low risk

The investigators describe a random component in the sequence generation process such as:

• random number table;

• computer random number generator;

• coin tossing;

• shuffling cards or envelopes;

• throwing dice;

• drawing of lots; or

• minimisation.*

*Minimisation may be implemented without a random element (treatment sums are equal), and this is considered to be equivalent to being random.

High risk

The researchers describe a (systematic or non‐systematic) non‐random component in the sequence generation process such as:

• systematic, non‐random approach

  • generating the sequence by, for example:

  • • odd or even date of birth;

    • date (or day) of admission;

    • hospital or clinic record number; or

    • alternation.

• non‐systematic, non‐random approach

  • allocating the participant by, for example:

  • • judgement of the clinician;

    • preference of the participant;

    • results of a laboratory test or a series of tests; or

    • availability of the intervention.

Unclear risk

Insufficient information to permit a judgment of ‘Low risk’ or ‘High risk’.

2. Allocation concealment (selection bias). For each RCT we will describe the method used to conceal the allocation sequence in sufficient detail to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment.

Low risk

Participants and investigators enrolling participants could not foresee assignment because one of the following, or an equivalent method, was used to conceal allocation:

• central allocation (including telephone, web‐based and pharmacy‐controlled randomisation);

• sequentially numbered drug containers of identical appearance; or

• sequentially numbered, opaque, sealed envelopes.

High risk

Participants or investigators enrolling participants could possibly foresee assignment and thus introduce selection bias because one of the following methods was used:

• open random allocation schedule (e.g. a list of random numbers);

• assignment envelopes without appropriate safeguards (e.g. if envelopes were unsealed or non‐opaque or not sequentially numbered);

• alternation or rotation;

• date of birth;

• case record number; or

• any other explicitly unconcealed procedure.

Unclear risk

Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’. This is usually the case if the method of concealment is not described or not described in sufficient detail to allow a definite judgment (e.g. if the use of assignment envelopes is described, but it remains unclear whether envelopes were sequentially numbered, opaque and sealed).

3. Blinding of participants and personnel (performance bias): objective outcomes. For each included trial, we will describe all methods used to blind trial participants and personnel from knowledge of which intervention a participant received. We will provide any information relating to whether the intended blinding was effective. We will assess blinding separately for different classes of outcomes. Outcomes will be divided into objective (e.g. cortisol) and subjective (e.g. self‐reported resilience and other psychological outcomes). We will consider the same outcomes at different time points.

Low risk

Any one of the following:

• no blinding or incomplete blinding, but the review authors judge that the outcome is not likely to be influenced by lack of blinding; or

• blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.

4. Blinding of participants and personnel (performance bias): subjective outcomes. For each included trial we will describe all methods used to blind trial participants and personnel from knowledge of which intervention a participant received. We will provide any information relating to whether the intended blinding was effective. We will assess blinding separately for different classes of outcomes. Outcomes will be divided into objective (e.g. cortisol) and subjective (e.g. self‐reported resilience and other psychological outcomes). We will consider the same outcomes at different time points.

Low risk

Blinding of participants and intervention providers, and unlikely that the blinding could have been broken.

High risk

Any one of the following:

• no blinding or incomplete blinding, and the outcome is likely to be influenced by lack of blinding; or

• blinding of key study participants and personnel attempted, but likely that the blinding could have been broken; and the outcome is likely to be influenced by the lack of blinding.

Unclear risk

Insufficient information to permit a judgment of ‘Low risk’ or ‘High risk’.

5. Blinding of outcome assessors (detection bias): objective outcomes. For each included trial we will describe all methods used to blind outcome assessors from knowledge of which intervention a participant received. We will provide any information relating to whether the intended blinding was effective. We will assess blinding separately for different classes of outcomes. Outcomes will be divided into objective (e.g. cortisol) and subjective (e.g. self‐reported resilience and other psychological outcomes). We will consider the same outcomes at different time points.

Low risk

Any one of the following:

• no blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding; or

• blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.

6. Blinding of outcome assessors (detection bias): subjective outcomes. For each included trial we will describe all methods used to blind outcome assessors from knowledge of which intervention a participant received. We will provide any information relating to whether the intended blinding was effective. We will assess blinding separately for different classes of outcomes. Outcomes will be divided into objective (e.g. cortisol) and subjective (e.g. self‐reported resilience and other psychological outcomes). We will consider the same outcomes at different time points.

Low risk

Any one of the following:

• no blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding; or

• blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.

High risk

Any one of the following:

• no blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding; or

• blinding of outcome assessment, but likely that the blinding could have been broken, and the outcome measurement is likely to be influenced by lack of blinding.

Unclear risk

Insufficient information to permit a judgment of ‘Low risk’ or ‘High risk’.

7. Incomplete outcome data (attrition bias). For each RCT we will describe the completeness of outcome data for each main outcome, including attrition and exclusions from the analysis. We will state whether attrition and exclusions were reported, the numbers included at each stage (compared with the total number of participants randomised), reasons for attrition or exclusions (where reported), and whether missing data were balanced across groups or were related to outcomes. Where sufficient data are reported, or can be provided by the trial authors, we will re‐include missing data in the analyses.

Low risk

Any one of the following:

• no missing outcome data;

• reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias);

• missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups;

• for dichotomous outcome data, the proportion of missing outcomes compared with observed event risk not enough to have a clinically relevant impact on the intervention effect estimate;

• for continuous outcome data, plausible effect size (difference in means or standardised difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size;

• missing data have been imputed using appropriate methods; or

• intention‐to‐treat; all randomised participants are analysed in the group to which they were allocated by randomisation, irrespective of noncompliance and co‐interventions.

High risk

Any one of the following:

• reason for missing outcome data likely to be related to true outcome, with either imbalance in numbers or reasons for missing data across intervention groups;

• for dichotomous outcome data, the proportion of missing outcomes compared with observed event risk is enough to induce clinically relevant bias in intervention effect estimate;

• for continuous outcome data, plausible effect size (difference in means or standardised difference in means) among missing outcomes enough to induce clinically relevant bias in observed effect size;

• potentially inappropriate application of simple imputation; or

• ‘as‐treated’ analysis done with substantial departure of the intervention received from that assigned at randomisation.

Unclear risk

Insufficient reporting of attrition or exclusions to permit a judgement of ‘Low risk’ or ‘High risk’ (e.g. number randomised not stated, no reasons for missing data provided, number of dropouts not reported for each group).

8. Selective outcome reporting (reporting bias). For each included trial we will describe how the possibility of selective outcome reporting was examined and what was found.

Low risk

Any of the following:

• the study protocol is available and all of the study’s pre‐specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre‐specified way; or

• the study protocol is not available, but it is clear that the published reports include all expected outcomes, including those that were pre‐specified (convincing text of this nature may be uncommon).

High risk

Any one of the following:

• not all of the study’s pre‐specified primary outcomes have been reported;

• one or more primary outcomes is reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not pre‐specified;

• one or more reported primary outcomes were not pre‐specified (unless clear justification for their reporting is provided such as an unexpected adverse effect);

• one or more outcomes of interest in the review are reported incompletely so that they cannot be entered in a meta‐analysis; or

• the study report fails to include results for a key outcome that would be expected to have been reported for such a study.

Unclear risk

Insufficient information to permit a judgment of ‘Low risk’ or ‘High risk’.