Users' Guides to the Medical Literature: II. How to Use an Article About Therapy or Prevention B. What Were the Results and Will They Help Me in Caring for My Patients?

CLINICAL SCENARIO You are a general internist who is asked to see a 65-year-old man with controlled hypertension and a 6-month history of atrial fibrillation resistant to cardioversion. Although he has no evidence for valvular or coronary heart disease, the family physician who referred him to you wants your advice on whether the benefits of long-term anticoagulants (to reduce the risk of embolic stroke) outweigh their risks (of hemorrhage from anticoagulant therapy). The patient shares these concerns and doesn't want to receive a treatment that would do more harm than good. You know that there have been randomized trials of warfarin for nonvalvular atrial fibrillation and decide that you'd better review one of them.