Assessments of attrition bias in Cochrane systematic reviews are highly inconsistent and thus hindering trial comparability

Ref ID 444
First Author A. Babic
Journal BMC MEDICAL RESEARCH METHODOLOGY
Year Of Publishing 2019
URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6451283/pdf/12874_2019_Article_717.pdf
Keywords • Missing data
• Cochrane
• General medical
• Risk of bias
Problem(s) • Flawed risk of bias undertaken
• Weaknesses identified in some Cochrane reviews
Article Type Empirical
Article Subtype Cross-sectional survey/Methodological systematic review
First Author Country Croatia
Checklists • Cochrane Risk of Bias
Aim To assess consistency of judgments and support for judgments of attrition bias in Cochrane reviews of interventions published in the Cochrane Database of Systematic Reviews from July 2015 to June 2016.
Level of Investigation Descriptive
Summary of Findings High inconsistency was found in the assessment of risk of bias related to incomplete outcome data, i.e. attrition bias in the included Cochrane reviews. Inconsistencies were found with the number of judgments, names of risk of bias domains and different judgments for the same supporting explanations, even within the same Cochrane review. One third of Cochrane review authors had more than one category of explanations; some had up to four different categories.
Number of systematic reviews included 729
Number of eligible systematic reviews assessed 955
Treatment impacted No
Treatment impacted description
Interpretation impacted Not Applicable
Interpretation impacted description