Recommendations by Cochrane Review Groups for assessment of the risk of bias in studies
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Open Access
- 21 April 2008
- journal article
- Published by Springer Science and Business Media LLC in BMC Medical Research Methodology
- Vol. 8 (1), 22
- https://doi.org/10.1186/1471-2288-8-22
Abstract
Assessing the risk of bias in individual studies in a systematic review can be done using individual components or by summarizing the study quality in an overall score. We examined the instructions to authors of the 50 Cochrane Review Groups that focus on clinical interventions for recommendations on methodological quality assessment of studies. Forty-one of the review groups (82%) recommended quality assessment using components and nine using a scale. All groups recommending components recommended to assess concealment of allocation, compared to only two of the groups recommending scales (P < 0.0001). Thirty-five groups (70%) recommended assessment of sequence generation and 21 groups (42%) recommended assessment of intention-to-treat analysis. Only 28 groups (56%) had specific recommendations for using the quality assessment of studies analytically in reviews, with sensitivity analysis, quality as an inclusion threshold and subgroup analysis being the most commonly recommended methods. The scales recommended had problems in the individual items and some of the groups recommending components recommended items not related to bias in their quality assessment. We found that recommendations by some groups were not based on empirical evidence and many groups had no recommendations on how to use the quality assessment in reviews. We suggest that all Cochrane Review Groups refer to the Cochrane Handbook for Systematic Reviews of Interventions, which is evidence-based, in their instructions to authors and that their own guidelines are kept to a minimum and describe only how methodological topics that are specific to their fields should be handled.Keywords
This publication has 37 references indexed in Scilit:
- Cochrane reviews compared with industry supported meta-analyses and other meta-analyses of the same drugs: systematic reviewBMJ, 2006
- Assessment of methodological quality of primary studies by systematic reviews: results of the metaquality cross sectional studyBMJ, 2005
- Empirical Evidence for Selective Reporting of Outcomes in Randomized TrialsJAMA, 2004
- Risks and Benefits of Estrogen Plus Progestin in Healthy Postmenopausal Women: Principal Results From the Women's Health Initiative Randomized Controlled TrialJAMA, 2002
- Uses and abuses of meta-analysisClinical Medicine, 2001
- Development of a quality assessment instrument for trials of treatments for depression and neurosisInternational Journal of Methods in Psychiatric Research, 2001
- Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta-analyses?The Lancet, 1998
- Assessing the quality of reports of randomized clinical trials: Is blinding necessary?Controlled Clinical Trials, 1996
- Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trialsJAMA, 1995
- Estrogen replacement therapy and coronary heart disease: A quantitative assessment of the epidemiologic evidencePreventive Medicine, 1991