Statistica Sinica 11(2001), 53-61
Abstract: A major problem in the analysis of clinical trials is missing data from patients who drop out of the study before the predetermined schedule. Shih and Quan (1997) proposed a ``composite'' (or ``pattern but not mix'') approach to the problem, which makes simultaneous inference on the conditional mean of the completers and the probability of completion or dropping out of the trial. Their method involves the combination of test statistics for the conditional mean and dropout probability. In this paper, we justify the asymptotic independence of the test statistics used in Shih and Quan.
Key words and phrases: Asymptotic independence, missing data, pattern-mixture modeling, Weiler's test.