title: A comparative study of tests for paired lifetime data.
abstract: In this paper, we investigate different procedures for testing the equality of two mean survival times in paired lifetime studies. We consider Owen's M-test and Q-test, a likelihood ratio test, the paired t-test, the Wilcoxon signed rank test and a permutation test based on log-transformed survival times in the comparative study. We also consider the paired t-test, the Wilcoxon signed rank test and a permutation test based on original survival times for the sake of comparison. The size and power characteristics of these tests are studied by means of Monte Carlo simulations under a frailty Weibull model. For less skewed marginal distributions, the Wilcoxon signed rank test based on original survival times is found to be desirable. Otherwise, the M-test and the likelihood ratio test are the best choices in terms of power. In general, one can choose a test procedure based on information about the correlation between the two survival times and the skewness of the marginal survival distributions.
authors.affiliation: Statistical Center for HIV/AIDS Research & Prevention, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Wang
authors.forename: Hon Keung Tony
authors.initials: HK
authors.lastname: Ng
mesh_terms: D001699:Biometry; D006801:Humans; D015993:Life Tables; D016013:Likelihood Functions; D015233:Models, Statistical; D009010:Monte Carlo Method; D016019:Survival Analysis