Evidence-based medicine: specific skills necessary for developing expertise in critical appraisal.

The concept of evidence-based medicine (EBM), defined as the integration of best research evidence with clinical expertise and patient values, is essential to the review, understanding, and application of clinical principles into the practice of medicine. Critical appraisal includes recognizing and evaluating various study designs and their ranking in order of priority, judging relevance to the question at hand, identifying potential sources of bias, and determining whether the data presentation, statistical analysis, and conclusions are appropriate. The focus of this article is on the quality of the evidence and how each step in critical appraisal is important to the overall concept and application of EBM.