Homogeneity Test of Ratio of Two Proportions in Stratified Bilateral Data

Homogeneity is a nonnegligible condition in the statistical analysis of the stratified bilateral data. The correlation between responses from two paired body parts should be taken into account to avoid biased or misleading results. In this article, we derive four test statistics (i.e., likelihood ratio statistic T_L, Wald-type statistic T_W, and score statistics T^a_SC and T^b_SC) for testing common ratios of two proportions across strata under the assumption of equal correlation coefficient within each stratum. Monte Carlo simulations show that the score test (T^b_SC) generally produces robust Type I error and satisfactory power. Two real examples are used to demonstrate the performance of the four proposed tests. Supplementary materials for this article are available online.