Users' Guides to The Medical Literature - XXV. Evidence-based medicine: Principles for applying the Users' Guides to patient care

This series provides clinicians with strategies and tools to interpret and integrate evidence from published research in their care of patients. The 2 key principles for applying all the articles in this series to patient car e relate to the value-laden nature of clinical decisions and to the hierarc hy of evidence postulated by evidence-based medicine. Clinicians need to be able to distinguish high from low quality in primary studies, systematic r eviews, practice guidelines, and other integrative research focused on mana gement recommendations. An evidence-based practitioner must also understand the patient's circumstances or predicament; identify knowledge gaps and fr ame questions to fill those gaps; conduct an efficient literature search; c ritically appraise the research evidence; and apply that evidence to patien t care. However, treatment judgments often reflect clinician or societal va lues concerning whether intervention benefits are worth the cost. Many unan swered questions concerning how to elicit preferences and how to incorporat e them in clinical encounters constitute an enormously challenging frontier for evidence-based medicine. Time limitation remains the biggest obstacle to evidence-based practice but clinicians should seek evidence from as high in the appropriate hierarchy of evidence as possible, and every clinical d ecision should be geared toward the particular circumstances of the patient .