Combination of Results from Several 2 x 2 Contingency Tables

Abstract

A weighted average of the difference between the 2 proportions in each contingency table is calculated, wherein the choice of weights is influenced by the relationship between the individual differences and the magnitude of the corresponding proportions. It is shown that some of the commonly used methods may be deduced as special cases of the above approach. Based on empirical work and considerations of asymptotic efficiencies, recommendations are made for the choice of weights in practical situations.