title: Use of two-stage test statistic in the two-period crossover trials.
abstract: For two-period crossover trials where the residual carryover can only exist in the presence of treatment effect, Willan (1988, Biometrics 44, 211-218) recommended use of the maximum test statistic that chooses the analysis with the larger test statistic corresponding to the parallel analysis and the crossover analysis. We construct two alternative two-stage test procedures, based on Grizzle's approach, that maintain the actual type I error rate at the desirable level. The power, accuracy, and precision of the analysis based on the modified two-stage procedures are compared to those based on the parallel analysis, crossover analysis, and the maximum test statistic.
authors.affiliation: Division of Biometrics I, CDER/FDA, Rockville, Maryland 20852, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Wang
authors.forename: H M
authors.initials: HM
authors.lastname: Hung
mesh_terms: D001699:Biometry / Q000379:methods; D018849:Controlled Clinical Trials as Topic / Q000379:methods*; D018592:Cross-Over Studies; D006801:Humans; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D013997:Time Factors