Single case studies in clinical trials.

The single case design offers an interesting alternative to standard methods of performing clinical trials. The opinion of the workshop members was that single case trials would be particularly useful in studies of rare diseases and in studies aimed at generation of hypothesis rather than testing of hypotheses. The single case design was considered to require smaller patient materials than ordinary methods in order to arrive at a valid conclusion about therapeutic effect. Dose ranging (Phase II) studies and studies of heterogenous patient populations were also discussed as possible areas of application for the single case design.