Associated factors and consequences of risk of bias in randomized controlled trials of yoga: A systematic review

Cramer, H; Langhorst, J; Dobos, G; Lauche, R

Associated factors and consequences of risk of bias in randomized controlled trials of yoga: A systematic review

Cramer, H Langhorst, J Dobos, G Lauche, R

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Publication Type:: Journal Article
Citation:: PLoS ONE, 2015, 10 (12)
Issue Date:: 2015-12-01

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Field	Value	Language
dc.contributor.author	Cramer, H	en_US
dc.contributor.author	Langhorst, J	en_US
dc.contributor.author	Dobos, G	en_US
dc.contributor.author	Lauche, R https://orcid.org/0000-0002-4171-7935	en_US
dc.date.available	2015-11-15	en_US
dc.date.issued	2015-12-01	en_US
dc.identifier.citation	PLoS ONE, 2015, 10 (12)	en_US
dc.identifier.uri	http://hdl.handle.net/10453/43569
dc.description.abstract	© 2015 Cramer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: Bias in randomized controlled trials (RCTs) of complementary therapy interventions seems to be associated with specific factors and to potentially distort the studies' conclusions. This systematic review assessed associated factors of risk of bias and consequences for the studies' conclusions in RCTs of yoga as one of the most commonly used complementary therapies. Methods: Medline/PubMed, Scopus, IndMED and the Cochrane Library were searched through February 2014 for yoga RCTs. Risk of selection bias was assessed using the Cochrane tool and regressed to a) publication year; b) country of origin; c) journal type; and d) impact factor using multiple logistic regression analysis. Likewise, the authors' conclusions were regressed to risk of bias. Results: A total of 312 RCTs were included. Impact factor ranged from 0.0 to 39.2 (median = 1.3); 60 RCT (19.2%) had a low risk of selection bias, and 252 (80.8%) had a high or unclear risk of selection bias. Only publication year and impact factor significantly predicted low risk of bias; RCTs published after 2001 (adjusted odds ratio (OR) = 12.6; 95% confidence interval (CI) = 1.7, 94.0; p<0.001) and those published in journals with impact factor (adjusted OR = 2.6; 95%CI = 1.4, 4.9; p = 0.004) were more likely to have low risk of bias. The authors' conclusions were not associated with risk of bias. Conclusions: Risk of selection bias was generally high in RCTs of yoga; although the situation has improved since the publication of the revised CONSORT statement 2001. Pre-CONSORT RCTs and those published in journals without impact factor should be handled with increased care; although risk of bias is unlikely to distort the RCTs' conclusions.	en_US
dc.relation.ispartof	PLoS ONE	en_US
dc.relation.isbasedon	10.1371/journal.pone.0144125	en_US
dc.subject.classification	General Science & Technology	en_US
dc.subject.mesh	Humans	en_US
dc.subject.mesh	Complementary Therapies	en_US
dc.subject.mesh	Meditation	en_US
dc.subject.mesh	Yoga	en_US
dc.subject.mesh	Logistic Models	en_US
dc.subject.mesh	Risk	en_US
dc.subject.mesh	Selection Bias	en_US
dc.subject.mesh	Randomized Controlled Trials as Topic	en_US
dc.title	Associated factors and consequences of risk of bias in randomized controlled trials of yoga: A systematic review	en_US
dc.type	Journal Article
utslib.citation.volume	12	en_US
utslib.citation.volume	10	en_US
utslib.for	1104 Complementary and Alternative Medicine	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Health
pubs.organisational-group	/University of Technology Sydney/Strength - CHSP - Health Services and Practice
utslib.copyright.status	open_access
pubs.issue	12	en_US
pubs.publication-status	Published	en_US
pubs.volume	10	en_US

Abstract:

© 2015 Cramer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: Bias in randomized controlled trials (RCTs) of complementary therapy interventions seems to be associated with specific factors and to potentially distort the studies' conclusions. This systematic review assessed associated factors of risk of bias and consequences for the studies' conclusions in RCTs of yoga as one of the most commonly used complementary therapies. Methods: Medline/PubMed, Scopus, IndMED and the Cochrane Library were searched through February 2014 for yoga RCTs. Risk of selection bias was assessed using the Cochrane tool and regressed to a) publication year; b) country of origin; c) journal type; and d) impact factor using multiple logistic regression analysis. Likewise, the authors' conclusions were regressed to risk of bias. Results: A total of 312 RCTs were included. Impact factor ranged from 0.0 to 39.2 (median = 1.3); 60 RCT (19.2%) had a low risk of selection bias, and 252 (80.8%) had a high or unclear risk of selection bias. Only publication year and impact factor significantly predicted low risk of bias; RCTs published after 2001 (adjusted odds ratio (OR) = 12.6; 95% confidence interval (CI) = 1.7, 94.0; p<0.001) and those published in journals with impact factor (adjusted OR = 2.6; 95%CI = 1.4, 4.9; p = 0.004) were more likely to have low risk of bias. The authors' conclusions were not associated with risk of bias. Conclusions: Risk of selection bias was generally high in RCTs of yoga; although the situation has improved since the publication of the revised CONSORT statement 2001. Pre-CONSORT RCTs and those published in journals without impact factor should be handled with increased care; although risk of bias is unlikely to distort the RCTs' conclusions.

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http://hdl.handle.net/10453/43569