In many clinical experiments, investigators collect data over time in an effort to test a particular research hypothesis. For ethical as well as practical reasons, the investigators might wish to monitor the data at interim analysis time-points to assess whether there is enough evidence to either reject or accept the research hypothesis and to terminate the study early if such evidence exists. Such an experiment is referred to as a group- sequential study. The overall goal is to develop a very general Microsoft Windows package for the design and interim monitoring of group- sequential clinical trials, within a single unified framework, based on the concepts of efficiency and statistical information. The software will: * perform group-sequential inference for the parameter of interest from practically any type of mathematical model including the entire family of generalized linear models, survival models, linear and non-linear mixed effects models, and semi-parametric models for longitudinal studies; * interface with commercially available design packages enabling them to convert fixed-sample studies into group-sequential ones; * permit adaptive redesign of the physical resources committed to a study at each interim monitoring-time point without altering the operating characteristics of the study. There exists no other design or interim monitoring software with all these capabilities.
It is now common practice for large scale clinical trials to be designed for possible early stopping and be monitored by independent data monitoring boards. This is mandatory for extramural trials sponsored by the National Cancer Institute. Increasingly monitoring boards are being established for pivotal cancer clinical trials conducted by individual pharmaceutical companies as well. Software to design and monitor such studies is scarce, while the economic and ethical benefits of stopping early, either for efficacy or futility, are enormous.
