  Adaptive trials are now mainstream science. Recently, researchers have taken
the adaptive trial concept to its natural conclusion, proposing what we call
"Global Cumulative Treatment Analysis" (GCTA). Similar to the adaptive trial,
decision making and data collection and analysis in the GCTA are continuous and
integrated, and treatments are ranked in accord with the statistics of this
information, combined with what offers the most information gain. Where GCTA
differs from an adaptive trial, or, for that matter, from any trial design, is
that all patients are implicitly participants in the GCTA process, regardless
of whether they are formally enrolled in a trial. This paper discusses some of
the theoretical and practical issues that arise in the design of a GCTA, along
with some preliminary thoughts on how they might be approached.
