Evidence-based medicine, part 1. An introduction to creating an answerable question and searching the evidence.

This article, the first in a series of six articles, introduces the concept of evidence-based medicine and describes the first two steps of practicing it: formulating an answerable clinical question and searching the available evidence. The types of clinical questions practitioners can ask are examined and a hierarchy of how to search for the best and most authoritative evidence is provided. The skills learned from creating an answerable question and searching the evidence, as outlined in this article, provide a solid basis for life-long learning and improved patient care.

Evidence-based medicine, part 2. An introduction to critical appraisal of articles on therapy.

This article provides an introductory step-by-step process to appraise a therapeutic article. The authors introduce these principles using a systematic approach and case-based format. The process of assessing the validity of a therapeutic article, determining its importance, and applying it to an individual patient is reviewed. The concepts of randomization, blinding, and concealment are discussed to help physicians determine an article's validity. Instruction on calculating relative risk reduction, absolute risk reduction, and number needed to treat is provided and applied to the clinical scenario. Finally, information that is learned from the previous two steps is applied to patient care. The skills learned from appraising a therapeutic article in the manner outlined provides a basis for life-long learning and improved patient care.