Perspectives in medicine. Generalizability of homogenous samples in clinical trials.

Clinicians face a tremendous challenge in staying abreast of the medical literature. They must be particularly cautious to assess the safety and efficacy of new tests and treatments. Advances in research methodology have led to increasing use of homogenous or restricted samples. While this may improve the quality of the research design and reduce costs, there is a loss of generalizability. Often journal reports do not provide sufficient information so the clinician can decide whether the data and results reported are applicable to a patient population. This is particularly important to clinicians whose patients come predominantly from "special populations." Investigators, journal editors and clinicians need to increase their efforts to maximize considerations of generalizability in clinical trials.