A discrete time sequential process for analyzing censored survival data using the likelihood ratio

✍ Scribed by A. Maul

• Book ID: 104340682
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 180 KB
• Volume: 71
• Category: Article
• ISSN: 0378-3758
• DOI: 10.1016/s0378-3758(98)00086-x

✦ Synopsis

A sequential testing procedure for comparing survival distributions with binary responses is considered. The data are monitored according to a discrete time process of reviewing the situation at regularly spaced intervals of time by using the likelihood ratio as a test statistic. Sampling continues until either a decision can be made about the hazard rates characterizing the survival distributions to be compared or a prespeciÿed time limit is reached. Monte Carlo simulations are used to model and estimate the power of the process. More speciÿcally, the critical threshold which allows one to control type-I error at a given level during the whole testing procedure is also determined empirically by simulation. Particular attention is paid to the gain of e ciency resulting from the sequential approach. The better understanding of the relative incidence of the parameters deÿning the experimental conditions on the power of the process is shown to be helpful in planning a proper experimental design for a wide range of comparative studies (e.g. clinical trials, environmental health studies). Two examples referring to survival data of couples trying to begin a pregnancy and patients with bladder cancer, including environmental or technical factors, are presented as an illustration.