Varying coefficient meta-analysis methods for odds ratios and risk ratios.

Odds ratios and risk ratios are useful measures of effect size in 2-group studies in which the response variable is dichotomous. Confidence interval methods are proposed for combining and comparing odds ratios and risk ratios in multistudy designs. Unlike the traditional fixed-effect meta-analysis methods, the proposed varying coefficient methods do not require effect-size homogeneity, and unlike the random-effects meta-analysis methods, the proposed varying coefficient methods do not assume that the effect sizes from the selected studies represent a random sample from a normally distributed superpopulation of effect sizes. The results of extensive simulation studies suggest that the proposed varying coefficient methods have excellent performance characteristics under realistic conditions and should provide useful alternatives to the currently used meta-analysis methods. (PsycINFO Database Record