Study designs in dermatology: A review for the clinical dermatologist.

A working knowledge of common research study designs and their advantages and disadvantages is necessary for critical reading of the literature by clinicians. However, understanding study designs and related statistical methodologies may be perceived as being complex and difficult to execute. This review aims to provide a practical foundation for basic study designs and to help physicians identify pitfalls that commonly occur in clinical studies and their level of evidence. Topics covered include the pros and cons of observational versus prospectively controlled studies, case-control, cohort, randomized controlled studies, adaptive controlled trials and metaanalyses, and the role of matching in studies.