On comparison of SAS codes with GLM and MIXED for the crossover studies with QT interval data

Abstract

The structural complexity of crossover studies for bioequivalence test confuses analysts and leaves them a hard choice among various programs. Our study reviews PROC GLM and PROC MIXED in SAS and compares widely used SAS codes for crossover studies. PROC MIXED based on REML is more recommended since it provides best linear unbiased estimator of the random between-subject effects and its variance. Our study also considers the covariance structure within subject over period which most PK/PD studies and crossover studies ignore. The QT interval data after the administra tion of moxifloxacin for a fixed time point are analyzed for the comparison of representative SAS codes for crossover studies.