Association between risk-of-bias assessments and results of randomized trials in Cochrane reviews: the ROBES meta-epidemiologic study

Ref ID 55
First Author J. Savović
Journal AMERICAN JOURNAL OF EPIDEMIOLOGY
Year Of Publishing 2018
URL https://pubmed.ncbi.nlm.nih.gov/29126260/
Keywords Cochrane
Author
Risk of bias
General medical
Problem(s) Flawed risk of bias undertaken
Number of systematic reviews included 228
Summary of Findings Bayesian analysis of 228 Cochrane meta-analyses found that intervention effect estimates were, on average, exaggerated in trials with high or unclear (versus low) risk-of-bias judgements for sequence generation (ratio of odds ratios (ROR) = 0.91, 95% credible interval (CrI): 0.86, 0.98), allocation concealment (ROR = 0.92, 95% CrI: 0.86, 0.98), and blinding (ROR = 0.87, 95%CrI: 0.80, 0.93). There was no consistently different bias for subjective outcomes compared with mortality. However, there was an increase in between-trial heterogeneity associated with lack of blinding in meta-analyses with subjective outcomes. Inconsistency in criteria for risk-of-bias judgements applied by individual reviewers is a likely limitation of routinely collected bias assessments. Inadequate randomization and lack of blinding may lead to exaggeration of intervention effect estimates in randomized trials.
Did the article find that the problem(s) led to qualitative changes in interpretation of the results? Yes
Are the methods of the article described in enough detail to replicate the study? No