Trials are often international in scope with many country-specific complications .
Those studies examining clinical endpoints or outcomes often require tens of thousands of patients and several hundred investigators. In all clinical trials there is a tendency to focus on results from the outset and to assume that adequate numbers of patients will be recruited. Study proposals dwell at length on the management of patients after they have been recruited, and give relatively little emphasis to recruitment itself. However, patient recruitment problems frequently arise and can jeopardize almost any study. The purpose of this paper is to discuss these problems and suggest strategies to minimize their impact.