A primer on clinical trial design.

A well-designed and executed clinical trial is the gold standard of evidence-based medicine. It is important for readers to understand the rationale for the study design, identify common pitfalls, and scrutinize limitations. Herein, we present a brief overview of types of designs used for clinical trials and discuss the use of appropriate end points, the selection of study participants, randomization, sample size calculation, blinding, and analysis of data. Finally, we emphasize the importance of accurate and transparent reporting. Our goal is to provide a primer for practicing urologists to enhance their understanding of the clinical trial literature.