The darker side of randomized trials: recruitment challenges.

Randomized trials are thought to provide optimal evidence if carried out correctly. Their application to important questions is the best guide to clinical decision-making. However, these trials are expensive to complete and have a variety of challenges in design and application. This article will review some of the factors that affect our ability to recruit patients into randomized controlled trials for conditions that may be treated surgically by different methods or for conditions for which both nonsurgical and surgical treatments exist.