Association between unreported outcomes and effect size estimates in Cochrane meta-analyses

Ref ID 637
First Author T. A. Furukawa
Journal JAMA
Year Of Publishing 2007
URL https://pubmed.ncbi.nlm.nih.gov/17284696/
Keywords • Cochrane
• General medical
Problem(s) • Multiplicity of outcomes and lack of pre-specification for outcome reporting
Article Type Editorial
Article Subtype Comment/letter
First Author Country Japan
Aim Research letter examining (1) to what extent Cochrane meta-analyses include only a proportion of identified RCTs when estimating treatment effects on patient- important outcomes and (2) whether the proportion of RCTs included in a meta-analysis is associated with its pooled effect size.
Level of Investigation Descriptive
Summary of Findings Approximately half of the RCTs identified by Cochrane reviews did not contribute to the pooled effect size estimates for patient-important outcomes in their meta-analyses. There appeared to be an inverse association between percentage of RCTs contributing and effect size.
Number of systematic reviews included 500
Number of eligible systematic reviews assessed 2524
Treatment impacted Yes
Treatment impacted description
Interpretation impacted No
Interpretation impacted description