How many patients in atrial fibrillation admitted to an acute medical unit will benefit from oral anticoagulation?: Application of the results of the major randomized controlled trials to 141 consecutive, unselected, elderly patients using a decision support computer program

Abstract

Background Although several randomized, control trials (RTC) suggest that oral anticoagulation (OAC) benefits patients with atrial fibrillation (AF), this might not be true for hospitalized patients with co-morbid conditions. If the results of the RTCs are valid, then how many patients in AF admitted to an acute medical unit will benefit from OAC? Methods An RCT-based decision analysis model calculated the quality-adjusted life expectancy (QALE) gain from OAC for 141 unselected consecutive patients over 65 years of age with AF admitted to an acute medical unit. Results If treated with aspirin, all 141 patients were predicted to gain QALE compared with placebo. If the quality of life adjustment (QoLA) on OAC was the same as placebo, then 104 patients were predicted to benefit from OAC compared with aspirin, while 63 patients were predicted to benefit at a QoLA of 0.99 (overall benefit 0.13±0.15 QALYs, range 0.01–0.88 QALYs). These 63 patients were more likely to have had a stroke, diabetes, hypertension, heart failure or heart attack, and less likely to have impaired renal function than those predicted not to benefit. The 78 patients predicted not to benefit from OAC included 11 younger patients without heart failure, hypertension, diabetes or cerebrovascular disease; the remaining 67 patients, however, were older, more likely to have heart failure and/or renal impairment and were at high risk of both stroke and bleeding. Conclusion An RCT-based decision analysis model suggests that more than half the patients in AF admitted to a small rural hospital with acute medical conditions are unlikely to benefit from OAC, while all will benefit from aspirin.