Michael C. Reade|Anthony Delaney|Michael Bailey|Derek C. Angus
Bench-to-bedside review: Avoiding pitfalls in critical care meta-analysis – funnel plots, risk estimates, types of heterogeneity, baseline risk and the ecologic fallacy
University of Pittsburgh|Royal North Shore Hospital|University of Sydney|The Alfred Hospital|Monash University|University of Pittsburgh
metaanalysis powerful tool demonstrating applicability concept beyond context individual clinical trials observational studies including exploration effects across different subgroups metaanalysis avoids simpsons paradox consistent effect constituent trials reversed results simply pooled metaanalysis critical care medicine made complicated however heterogeneous nature critically ill patients contexts within treated failure properly adjust heterogeneity risks missing important subgroup effects example interaction treatment varying levels baseline risk subgroups defined characteristics vary within constituent trials age rather features constant within trial drug dose additional risk incorrect conclusions due ecological fallacy present review explains problems strategies overcome