Inspiratory muscle training for cystic fibrosis

Brian W Houston; Nicola Mills; Arturo Solis‐Moya

doi:10.1002/14651858.CD006112.pub2

Inspiratory muscle training for cystic fibrosis

Contraer todo Desplegar todo

Referencias

References to studies included in this review

Ir a:

estudios excluidos
otras referencias

Albinni S, Rath R, Renner S, Eichler I. Additional inspiratory muscle training intensifies the beneficial effects of cycle ergonometer training in patients with cystic fibrosis [abstract]. Journal of Cystic Fibrosis 2004;3(Suppl1):S63.

Google Scholar

Eichler I, Renner S, Albinni S, Nachbaur E, Rath R. Inspiratory muscle training adds beneficial effects to cycle ergometer training in patients with cystic fibrosis [abstract]. Pediatric Pulmonology 2005;40(Suppl 28):320.

Google Scholar

Amelina E, Cherniak A, Chikina S, Krasovsky S, Appaeva A. Inspiratory muscle training (IMT) in cystic fibrosis adults [abstract]. European Respiratory Society Annual Congress. 2006; Vol. Sep 2‐6; Munich, Germany:716s. [Abstract Number: P4112]

Google Scholar

Asher MI, Pardy RL, Coates AL, Thomas E, Macklem PT. The effects of inspiratory muscle training in patients with cystic fibrosis. American Review of Respiratory Disease 1982;126(5):855‐9.

Google Scholar

Asher MI, Pardy RL, Coates AL, Thomas E, Macklem PT. The effects of inspiratory muscle training in patients with cystic fibrosis. Australian and New Zealand Journal of Medicine (Annual Clinical and Scientific meeting for New Zealand Fellows and Advanced Trainees). 1983; Vol. 13:204.

Google Scholar

Chatham K, Ionescu A, Davies C, Baldwin J, Enright S, Shale DJ. Through range computer generated inspiratory muscle training in cystic fibrosis [abstract]. Pediatric Pulmonology 1997;24(Supplement 14):299. [Abstract Number: 340]

Google Scholar

de Jong W, van Aalderen WM, Kraan J, Koeter GH, van der Schans CP. Inspiratory muscle training in patients with cystic fibrosis. Respiratory medicine 2001;95(1):31‐36.

Enright S, Chatham K, Ionescu AA, Shale DJ, Unnithan V. A randomised double blind controlled trial of inspiratory muscle training in cystic fibrosis [abstract]. American Journal of Respiratory and Critical Care Medicine 2000;161(3 Suppl):A753.

Google Scholar

Enright S, Chatham K, Ionescu AA, Unnithan VB, Shale DJ. Inspiratory muscle training improves lung function and exercise capacity in adults with cystic fibrosis. Chest 2004;126(2):405‐11.

Campbell A, Enright S, Unnitham V. The effect of inspiratory muscle training on the measurement of resting energy expenditure in adult patients with cystic fibrosis and in health subjects [abstract]. European Respiratory Journal 2000;16(Suppl 31):153S.

Google Scholar

Heward C, Enright S, Chatham K, Ionescu AA, Shale DJ, Unnitham V. The effect of inspiratory muscle training on lung volumes and diaphragm structure in cystic fibrosis patients and in healthy subjects [abstract]. European Respiratory Journal 2000;16(Suppl 31):153S.

Google Scholar

Withnall L, Enright S, Chatham K, Ionescu AA, Shale DJ, Unnitham V. The effect of inspiratory muscle training on exercise capacity and inspiratory muscle function in cystic fibrosis patients and in healthy subjects [abstract]. European Repiratory Journal 2000;16(Suppl31):330S.

Google Scholar

Sawyer EH, Clanton TL. Improved pulmonary function and exercise tolerance with inspiratory muscle conditioning in children with cystic fibrosis. Chest 1993;104(5):1490‐7.

References to studies excluded from this review

Ir a:

estudios incluidos
otras referencias

Howard J, Bradley J, Hewitt O, Elborn S. The active cycle of breathing (ACBT) is a more effective method of airway clearance in cystic fibrosis (CF) patients than the test of incremental respiratory endurance (TIRE) [abstract]. Pediatric Pulomonology 2000;30(Supplement 20):304. [Abtract Number:457]

Google Scholar

Keens TG, Krastins IRB, Wannamaker E, Levison H, Crozier DN, Bryan AC. Ventilatory muscle endurance training in normal subjects and patients with cystic fibrosis. American Review of Respiratory Disease 1977;116(5):853‐60.

Google Scholar

Sartori R, Barbi E, Poli F, Ronfani L, Marchetti F, Amadde O, et al. Respiratory training with a specific device in cystic fibrosis: a prospective study. Journal of Cystic Fibrosis 2008;7(4):313‐19.

Additional references

Ir a:

estudios incluidos
estudios excluidos

Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ 1995;311:485.

Bradley J, Moran F. Physical training for cystic fibrosis. Cochrane Database of Systematic Reviews 2008, Issue 1. [DOI: 10.1002/14651858.CD002768.pub2]

Cystic Fibrosis Trust. Making a Difference: Annual Report 2005 [online]. http://www.cftrust.org.uk/scope/documentlibrary/Publications/CF‐TrustAnnualReview2005.pdf (accessed 24 August 2005).

UK Cystic Fibrosis Trust. What is Cystic Fibrosis?. http://www.cftrust.org.uk/aboutcf/whatiscf/ (accessed 25th October 2007).

Chatham K, Ionescu AA, Nixon LS, Shale DJ. A short‐term comparison of two methods of sputum expectoration in cystic fibrosis. European Respiratory Journal 2004;23(3):435‐9.

Curtin F, Altman DG, Elbourne E. Meta‐analysis combining parallel and cross‐over clinical trials. I: Continuous outcomes. Statistics in Medicine 2002;21:2131‐44. [DOI: 10.1002/sim.1205]

Curtin F, Altman DG, Elbourne E. Meta‐analysis combining parallel and cross‐over clinical trials. II: Binary outcomes. Statistics in Medicine 2002;21:2145‐59. [DOI: 10.1002/sim.1206]

Curtin F, Altman DG, Elbourne E. Meta‐analysis combining parallel and cross‐over clinical trials. III: The issue of carryover. Statistics in Medicine 2002;21:2161‐73. [DOI: 10.1002/sim.1207]

Dodge JA, Lewis PA, Stanton M, Wilsher J. Cystic Fibrosis mortality and survival in the UK: 1947 ‐2003. European Respiratory Journal 2007;29(3):522‐6.

Elbourne DR, Altman DG, Higgins JPT, Curtin F, Worthington HV, Vail A. Meta‐analyses involving cross‐over trials: methodological issues. International Journal of Epidemiology 2002;31(1):140‐9.

Enright S, Chatham K, Baldwin J, Griffiths H. The effect of fixed load incremental inspiratory muscle training in the elite athlete: a pilot study. Physical Therapy in Sport 2000;1(1):1‐5.

Higgins JPT, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta‐analyses. BMJ 2003;327(7414):557‐60.

Editors: Julian PT Higgins and Douglas G Altman on behalf of the Cochrane Statistical Methods Group and the Cochrane Bias Methods Group. Chapter 8: Assessing risk of bias in included studies. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Jonathan J Deeks, Julian PT Higgins and Douglas G Altman on behalf of the Cochrane Statistical Methods Group. Chapter 9: Analysing data and undertaking meta‐analyses. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Kosorok MR, Wei WH, Farrell PM. The incidence of cystic fibrosis. Statistics in Medicine 1996;15(5):449‐6.

McClarey M, Duff L. Clinical effectiveness and evidence‐based practice. Nursing standard: official newspaper of the Royal College of Nursing 1997;11(52):33‐7.

McConnell A. Clinical implications of inspiratory muscle training [online]. http://www.powerbreathe.com/pdf/inspiratory‐muscle.pdf (accessed 24 August 2005).

O'Brien K, Geddes L, Reid D, Brooks D, Crowe J. Inspiratory muscle training compared with other rehabilitation interventions in chronic obstructive pulmonary disease. Journal of Cardiopulmonary Rehabilitation and Prevention 2008;28(2):128‐41.

World Health Organisation. Genes and human disease [online]. http://www.who.int/genomics/public/geneticdiseases/en/index.html (accessed August 24 2005).

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Ir a:

estudios excluidos

Albinni 2004

Methods	Parallel design over 12 weeks
Participants	n = 27 Age range: 6 ‐ 18 years Gender mix: no information
Interventions	IMT: no details; plus, cycle ergometer training 3 times per week Control: cycle ergometer training 3 times per week
Outcomes	FEV₁, FVC, IMS, IME, MEC, perceived breathlessness, antibiotic use and ease or degree of expectoration
Notes	IME protocol: abstract only, no details given
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, no details given
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: clear difference between the interventions received Dectection bias: No reference to any blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information provided. Intention to treat: unclear
Selective reporting (reporting bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Amelina 2006

Methods	Parallel design over six weeks
Participants	n = 20 Age range was not stated Gender mix: no information
Interventions	Threshold loading device: Intervention group: 30% of PI_max Control group: 7cm H₂O Training regimen: 10 to 15 minutes bd for 6 weeks
Outcomes	FEV₁, FVC, PI_max, IC, RMS, RME and exercise capacity
Notes	Abstract only
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The authors only state that the allocation was random without explaining the process involved
Allocation concealment (selection bias)	Unclear risk	No details are provided
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: The comparison group are referred to only as the "control group" with no mention of the intensity of the training used; i.e. if it was at "sham" or sub‐maximal levels Dectection bias: No reference to any blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	No statistical data is presented for the control group. One subject from the intervention group did not complete the trial; it was not stated whether they were included or excluded from the final analysis
Selective reporting (reporting bias)	High risk	Two outcomes (respiratory muscle strength and dyspnoea) are mentioned as having been analysed, but no data are provided for them.
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Asher 1983

Methods	Consecutive, self‐control design over 8 weeks
Participants	n = 11 Age range: 9 ‐ 24 years Gender mix: no information
Interventions	IMT: Inspiratory resistance, 15 minutes bd, no dosage Control: no details provided
Outcomes	IMS, W_max, VO₂max, VE and heart rate
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, no details given
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: no details of the control training regimen are provided = high risk Dectection bias: observer blind = low risk
Incomplete outcome data (attrition bias) All outcomes	High risk	Two participants were unable to satisfactorily perform the outcome measure PI_Max, due to expiration up to residual volume resulting in coughing. The authors do not stipulate whether this occurred during the intervention or control phase of the trial. Intention to treat: unclear
Selective reporting (reporting bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Chatham 1997

Methods	Parallel design over 8 weeks
Participants	Intervention: n = 9 Control: n = 9 No data was provided on the ages of the participants
Interventions	Intervention: Computer‐generated through range inspiratory muscle training (TIRE) at 80% of individual capacity Control: Threshold loading device at 30% of peak; the measure used is not named
Outcomes	Chronic Respiratory Disease Questionnaire ('mastery' and 'emotion' elements), RMS and RME
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, no details given
Allocation concealment (selection bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Blinding (performance bias and detection bias) All outcomes	High risk	Perfomance bias: the training intensities employed (80% and "threshold" 30% training) could, potentially, have led the participants to know which group they were in Dectection bias: no reference to any blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information available to arrive at a conclusion; no statistical data is presented for the control group Intention to treat: 3 from 18 (17%)
Selective reporting (reporting bias)	Unclear risk	As this study (to date) is only published in abstract form it is unclear whether the reported outcomes are all that were analysed.
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

de Jong 2001

Methods	Parallel design over 6 weeks
Participants	Intervention: n = 8; mean (SD) age = 17 (5.2) years Control: n = 8; mean (SD) age = 19 (5.5) years
Interventions	IMT: Threshold loading; 20 minutes a day, 5 days per week. At 40% of PI_max Control: Threshold loading; 20 minutes a day, 5 days per week. At 10% of PI_max
Outcomes	FEV₁, FVC, W_max, VO₂max, VE_max, IME, perceived breathlessness, general fatigue, physical fatigue, reduced activity score, reduced motivation score, mental fatigue and dyspnoea
Notes	IME protocol: a commercially‐available threshold‐loading device (Threshold, Healthscan Products, Inc. U.S.A.) was used during an incremental loading procedure. In order to obtain pressures over 41 cm H₂O an additional spring was inserted with a double‐spring constant. Participants started inspiring from a threshold‐loading device set at 30% of PI_max for 2 min. The threshold load was then increased every 2 min in increments of 10% of Pimax. The maximal load was defined as the highest load which could be reached and maintained for at least 1 min as a percentage of PI_max. The breathing pattern was not regulated.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Minimisation
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: both training intensities were low; however, no attempt was made to ascertain whether the participants knew if the received the training intensity Detection bias: no reference to any blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	One participant in the intervention group was withdrawn due to earache experienced whilst training at 40% of PI_max Intention to treat: 1 from 15 (6%)
Selective reporting (reporting bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Enright 2004

Methods	Parallel design over 8 weeks
Participants	All participants: n = 29, mean (SD) age = 22 (4.2) years Intervention 1: n = 9, mean (SD) age = 24.8 (5.5) years Intervention 2: n = 10, mean (SD) age = 20 (4.7) years Control: n = 6, mean (SD) age = 21.3 (2.7) years
Interventions	Intervention 1: IMT at 80% of "maximal inspiratory effort" Intrevention 2: IMT at 20% of "maximal inspiratory effort" IMT: Incremental maximal effort with progressively shorter rest periods, 3 times a week Control: "No Training"
Outcomes	FEV₁(% predicted), FVC (% predicted), PI_max, SPI_max, heart rate, perceived exertion, dyspnoea and Chronic Respiratory Disease Questionnaire
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: the comparison was "no training" making it clear to the participants which arm they were in Dectection bias: outcome assessors at the final data collection session, although they did not state whether this was the case at the initial assessment or even if the same assessors carried out all the assessments
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention is made of whether all subjects completed the trial or not. Nor are there any statistical indications Intention to treat: unclear
Selective reporting (reporting bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Heward 2000

Methods	Parallel design over 8 weeks
Participants	Experimental: n = 19, mean (SD) age = 22.5 (3.5) years Control: n = 20, mean (SD) age = 21.5 (3.5) years Gender matched groups
Interventions	IMT: IMT at 80% of "maximal effort". No dosage stated 3 control groups: healthy participants: IMT at 80% of "maximal effort"; healthy participants: "No Training" and CF participants: "No Training"
Outcomes	VC, TLC
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, no details given
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: the comparison was "no training" making it clear to the participants which arm they were in Detection bias: no reference to any blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information provided Intention to treat: unclear
Selective reporting (reporting bias)	High risk	The post‐training pulmonary function results were not presented
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

Sawyer 1993

Methods	Parallel design over 10 weeks
Participants	Experimental: n = 10, mean (SD) age = 11.46 (2.45) Sham: n = 10, mean (SD) age = 9.76 (2.57)
Interventions	IMT: IMT at 60% PI_max Control: IMT at 10% PI_max
Outcomes	FEV₁, VC, FRC, IC, RV, TLC, RV/TLC, FEV₁/FVC, MVV, exercise time
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, no details given
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Performance bias: there was a clear difference in the intensity of training although no attempt was made to ascertain whether the participants in the training groups knew if they received the training intensity Dectection bias: outcome assessors at the final data collection session, although they did not state whether this was the case at the initial assessment or even if the same assessors carried out all the assessments
Incomplete outcome data (attrition bias) All outcomes	High risk	2 participants removed from analysis and the reasons for this were explained; however, it is unclear which group(s) they were in Intention to treat: unclear
Selective reporting (reporting bias)	Unclear risk	Insufficient information available to arrive at a conclusion
Other bias	Unclear risk	Insufficient information available to arrive at a conclusion

% predicted: the volume of air exhaled expressed as a percentage of the expected volume based on the physical attributes of the individual
bd: twice a day
FEV₁: volume of air exhaled over the first second of a forced exhalation
FEV₁/FVC = the ratio of FEV₁ to FVC
FRC: functional residual capacity
FVC: total volume of air forcibly exhaled
FEF 25‐75%: forced expiratory flow 25‐75%
IC: inspiratory capacity
IME: inspiratory muscle endurance
IMF: inspiratory muscle function
IMS: inspiratory muscle strength
IMT: inspiratory muscle training
MEC: maximal exercise capacity
MVV: maximum voluntary ventilation
RME: respiratory muscle endurance
RMS: respiratory muscle strength
n: number of participants
PI_max: maximal inspiratory pressure
RV: residual volume; i.e. the volume of air retained in the lungs following a maximal, voluntary exhalation (FVC)
RV/TLC: the ratio of residual volume to total lung capacity
SD: standard deviation
SPI_max: sustained maximal inspiratory pressure
TLC: total lung capacity; i.e. the calculated maximum potential volume of an individual's lungs
VC: the total volume of air that can be exhaled in any one breath
VE(max): peak expired ventilation
VO₂max: peak oxygen consumption
W_max: maximum work load

Characteristics of excluded studies [ordered by study ID]

Ir a:

estudios incluidos

Study	Reason for exclusion
Howard 2000	Study excluded as the intervention was not inspiratory muscle training
Keens 1977	Study excluded as allocation not randomised
Sartori 2008	Observational study, no randomisation

Data and analyses

Open in table viewer

Comparison 1. IMT (80% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.1 Comparison 1 IMT (80% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).
1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.2 Comparison 1 IMT (80% of maximal effort) versus control, Outcome 2 Forced vital capacity (litres).
2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Chronic Respiratory Disease Questionnaire (mastery) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.3 Comparison 1 IMT (80% of maximal effort) versus control, Outcome 3 Chronic Respiratory Disease Questionnaire (mastery).
4 Chronic Respiratory Disease Questionnaire (emotion) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.4 Comparison 1 IMT (80% of maximal effort) versus control, Outcome 4 Chronic Respiratory Disease Questionnaire (emotion).

Open in table viewer

Comparison 2. IMT (60% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.1 Comparison 2 IMT (60% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).
1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 PImax (cmH2O) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.2 Comparison 2 IMT (60% of maximal effort) versus control, Outcome 2 PImax (cmH2O).
2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Open in table viewer

Comparison 3. IMT (40% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.1 Comparison 3 IMT (40% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).
1.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced expiratory volume at one second (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.2 Comparison 3 IMT (40% of maximal effort) versus control, Outcome 2 Forced expiratory volume at one second (% predicted).
2.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.3 Comparison 3 IMT (40% of maximal effort) versus control, Outcome 3 Forced vital capacity (litres).
3.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Forced vital capacity (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.4 Comparison 3 IMT (40% of maximal effort) versus control, Outcome 4 Forced vital capacity (% predicted).
4.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Inspiratory muscle endurance (%PImax) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.5 Comparison 3 IMT (40% of maximal effort) versus control, Outcome 5 Inspiratory muscle endurance (%PImax).
5.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Open in table viewer

Comparison 4. IMT (20% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.1 Comparison 4 IMT (20% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).
1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced expiratory volume at one second (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.2 Comparison 4 IMT (20% of maximal effort) versus control, Outcome 2 Forced expiratory volume at one second (% predicted).
2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.3 Comparison 4 IMT (20% of maximal effort) versus control, Outcome 3 Forced vital capacity (litres).
3.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Analysis 1.1

Comparison 1 IMT (80% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 1.2

Comparison 1 IMT (80% of maximal effort) versus control, Outcome 2 Forced vital capacity (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 1.3

Comparison 1 IMT (80% of maximal effort) versus control, Outcome 3 Chronic Respiratory Disease Questionnaire (mastery).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 1.4

Comparison 1 IMT (80% of maximal effort) versus control, Outcome 4 Chronic Respiratory Disease Questionnaire (emotion).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 2.1

Comparison 2 IMT (60% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 2.2

Comparison 2 IMT (60% of maximal effort) versus control, Outcome 2 PImax (cmH2O).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 3.1

Comparison 3 IMT (40% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 3.2

Comparison 3 IMT (40% of maximal effort) versus control, Outcome 2 Forced expiratory volume at one second (% predicted).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 3.3

Comparison 3 IMT (40% of maximal effort) versus control, Outcome 3 Forced vital capacity (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 3.4

Comparison 3 IMT (40% of maximal effort) versus control, Outcome 4 Forced vital capacity (% predicted).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 3.5

Comparison 3 IMT (40% of maximal effort) versus control, Outcome 5 Inspiratory muscle endurance (%PImax).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 4.1

Comparison 4 IMT (20% of maximal effort) versus control, Outcome 1 Forced expiratory volume at one second (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 4.2

Comparison 4 IMT (20% of maximal effort) versus control, Outcome 2 Forced expiratory volume at one second (% predicted).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Analysis 4.3

Comparison 4 IMT (20% of maximal effort) versus control, Outcome 3 Forced vital capacity (litres).

Ir a la figura de la revisiónAbrir en una pestaña nueva

Table 1. Explanation of terms

Term	Explanation
Continuous training	Training at 70% to 80% of maximum effort for 30 to 45 minutes. The percentage of maximal effort and/or the duration of the training may be adjusted depending on the goal of the training.
Elastic load	Refers to the load imposed by the stiffness of the lung and chest wall that must be overcome by the inspiratory muscles in order to generate inspiratory flow. Elastic loads are greater when breathing from a higher lung volume as a consequence of the associated decrease in lung and chest wall compliance. Imposing elastic loads has not been used to train the inspiratory muscles most likely due to the need for complicated equipment and poor clinical utility.
Forced expiratory volume at 1 second (FEV1)	The volume of air expelled during the 1st second of forced exhalation from total lung capacity.
Forced vital capacity (FVC)	The total volume of air expelled during a forced exhalation from total lung capacity.
Inspiratory capacity (IC)	The maximum volume of air taken into the lungs during a maximal inhalation from functional residual capacity.
Forced expiratory flow 25‐75% (FEF 25‐75%)	The speed of the air leaving the lungs during the middle section of a forced exhalation.
Interval Training	Periods of intense training interspersed with periods of recuperation. As with continuous training, the level of effort required during the training period may be adjusted to suit the individual and the intended goal. The period of recuperation will be adjusted accordingly.
Maximal inspiratory pressure [PI_max]	The maximum pressure generated by the inspiratory muscles against an occluded airway.
Resistive loading	Requires person to breathe through a narrow Inspiratory pathway/aperture. The load imposed is dependent on inspiratory flow, i.e. when using resistive training devices, participants can reduce the load imposed by manipulating their breathing pattern. Breathing pattern, specifically inspiratory flow, should be controlled when using resistive inspiratory muscle training devices.
Threshold loading	Requires the person to inspire through a device which imposes a threshold load via either a weighted plunger system or a spring‐loaded valve. The person needs to generate a critical inspiratory pressure, prior to the threshold valve opening and allowing inspiratory flow. Once the threshold valve is open, pressure and flow are largely independent and therefore the person is unable to reduce the load imposed by the device by manipulations in breathing pattern.
Total lung capacity (TLC)	The maximum amount of air the lungs can hold when they are fully inflated.
Voluntary isocapnic (normocapnic) hyperpnoea	Requires the person to maintain a high level of minute ventilation for a specified period. Imposes a high flow, low pressure load on the inspiratory muscles which is analogous to the loads borne by the inspiratory muscles during periods of increased minute ventilation (i.e. during exercise). Requires the use of complex equipment to ensure stable levels of carbon dioxide in the arterial blood (PaCO2), so is rarely used in the clinical setting.

Table 1. Explanation of terms

Ir a la tabla de la revisión

Comparison 1. IMT (80% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Chronic Respiratory Disease Questionnaire (mastery) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

4 Chronic Respiratory Disease Questionnaire (emotion) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

Comparison 1. IMT (80% of maximal effort) versus control

Ir a la tabla de la revisión

Comparison 2. IMT (60% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 PImax (cmH2O) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Comparison 2. IMT (60% of maximal effort) versus control

Ir a la tabla de la revisión

Comparison 3. IMT (40% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

1.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced expiratory volume at one second (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

2.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

3.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Forced vital capacity (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

4.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Inspiratory muscle endurance (%PImax) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

5.1 Less than two months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Comparison 3. IMT (40% of maximal effort) versus control

Ir a la tabla de la revisión

Comparison 4. IMT (20% of maximal effort) versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Forced expiratory volume at one second (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

1.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Forced expiratory volume at one second (% predicted) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

2.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Forced vital capacity (litres) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

3.1 Two to six months	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Comparison 4. IMT (20% of maximal effort) versus control

Ir a la tabla de la revisión

	Idioma de la Revisión Cochrane Escoja su idioma de preferencia para las revisiones Cochrane y otros contenidos. Las secciones sin una traducción aparecerán en inglés.

	Idioma de la web Escoja su idioma de preferencia para la web de la Biblioteca Cochrane.

Idioma de la Revisión Cochrane

Idioma de la web

Referencias

References to studies included in this review

Albinni 2004 {published data only}

Amelina 2006 {published data only}

Asher 1983 {published data only}

Chatham 1997 {published data only}

de Jong 2001 {published data only}

Enright 2004 {published data only}

Heward 2000 {published data only}

Sawyer 1993 {published data only}

References to studies excluded from this review

Howard 2000 {published and unpublished data}

Keens 1977 {published data only}

Sartori 2008 {published data only}

Additional references

Altman 1995

Bradley 2008

CF Trust 2005

CF Trust 2007

Chatham 2004

Curtin 2002a

Curtin 2002b

Curtin 2002c

Dodge 2007

Elbourne 2002

Enright 2000

Higgins 2003

Higgins 2011a

Higgins 2011b

Kosorok 1996

McClarey 1997

McConnell 2002

O'Brien 2008

WHO 2005

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Characteristics of excluded studies [ordered by study ID]

Data and analyses

Copiar o descargar referencia

Idioma de la Revisión Cochrane

Idioma de la web

Instituciones a las que se accedió previamente

Usuarios institucionales

Instituciones a las que se accedió previamente

Otras opciones de acceso