We provide a program to illustrate interactions between treatment and covariates or between two covariates by using forest plots under either the Cox proportional hazards or the logistic regression model. The program is flexible in both the possibility of illustrating more than one interaction...

In 2005, Barthel, Royston, and Babiker presented a menu-driven Stata program under the generic name of ART (assessment of resources for trials) to calculate sample size and power for complex clinical trial designs with a time-to- event or binary outcome. In this article, we describe a Stata tool...

We present menu- and command-driven Stata programs for the calculation of sample size, number of events, and trial duration for a novel type of clinical trial design with a time-to-event outcome and two or more experimental arms. The approach is based on terminating accrual of patients to...

Royston and Babiker (2002) presented a menu-driven Stata program for the calculation of sample size or power for complex clinical trial designs under a survival time or binary outcome. In the present article, the package is updated to Stata 8 under the new name ART. Furthermore, the program has...