Critical evaluation of clinical research.

This focused review contains a suggested core of material that will help residents or practicing physiatrists critically review research papers published in the medical literature. Before accepting the results of a clinical trial, physiatrists must critique the experimental methods and study design carefully to decide whether to include these new ideas into their clinical practice. Medical research relies on statistical methodology, and statistics pervade the medical literature. This article begins with an introduction to rudimentary statistics. Fortunately, most studies depend on a rather small body of statistical concepts. The elements of experimental design--clinical trials, randomization, single-subject design, meta-analysis, epidemiological studies--are presented in a concise review. Finally, the elements of statistics and experimental design are integrated into a step-by-step method strategy for reading the medical literature.