Phase I clinical trials are conducted in order to find the maximum tolerated dose of a given drug out of a set of doses, usually finite. In general, once a formal target function and a suitable probability structure are defined, optimization of sequential studies can theoretically be achieved...

Ranked set sampling (RSS) is a technique for incorporating auxiliary (concomitant) information into estimation and testing procedures right at the design stage. In this paper, we propose group sequential testing procedures for comparing two treatments with binary outcomes under an RSS scheme...

The evidence-based perspective to sample size estimation determines appropriate trial size by examining its potential impact on the literature. This approach is extended to determine the appropriate size of a planned cluster randomized trial by considering the role of the planned trial on a...