Between-trial heterogeneity in meta-analyses may be partially explained by reported design characteristics.
J Clin Epidemiol
; 95: 45-54, 2018 03.
Article
in En
| MEDLINE
| ID: mdl-29217451
ABSTRACT
OBJECTIVE:
We investigated the associations between risk of bias judgments from Cochrane reviews for sequence generation, allocation concealment and blinding, and between-trial heterogeneity. STUDY DESIGN ANDSETTING:
Bayesian hierarchical models were fitted to binary data from 117 meta-analyses, to estimate the ratio λ by which heterogeneity changes for trials at high/unclear risk of bias compared with trials at low risk of bias. We estimated the proportion of between-trial heterogeneity in each meta-analysis that could be explained by the bias associated with specific design characteristics.RESULTS:
Univariable analyses showed that heterogeneity variances were, on average, increased among trials at high/unclear risk of bias for sequence generation (λË 1.14, 95% interval 0.57-2.30) and blinding (λË 1.74, 95% interval 0.85-3.47). Trials at high/unclear risk of bias for allocation concealment were on average less heterogeneous (λË 0.75, 95% interval 0.35-1.61). Multivariable analyses showed that a median of 37% (95% interval 0-71%) heterogeneity variance could be explained by trials at high/unclear risk of bias for sequence generation, allocation concealment, and/or blinding. All 95% intervals for changes in heterogeneity were wide and included the null of no difference.CONCLUSION:
Our interpretation of the results is limited by imprecise estimates. There is some indication that between-trial heterogeneity could be partially explained by reported design characteristics, and hence adjustment for bias could potentially improve accuracy of meta-analysis results.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Research Design
/
Meta-Analysis as Topic
Type of study:
Prognostic_studies
/
Systematic_reviews
Limits:
Humans
Language:
En
Journal:
J Clin Epidemiol
Journal subject:
EPIDEMIOLOGIA
Year:
2018
Document type:
Article