Increasing US Emergency Department Visit Rates and Subsequent Hospital Admissions for Atrial Fibrillation from 1993 to 2004

Abstract

Atrial fibrillation is a significant public health problem that is becoming increasingly prevalent. The clinical epidemiology of US emergency department (ED) visits for atrial fibrillation is uncertain. This study seeks to describe recent trends in ED visits for atrial fibrillation. ED visits with a primary diagnosis of atrial fibrillation were analyzed using data from the US National Hospital Ambulatory Medical Care Survey, 1993 to 2004. During the 12-year period, there were approximately 2.7 million (95% confidence interval [CI] 2.4 to 3.0 million) ED visits for atrial fibrillation in the United States, and the population-adjusted visit rate increased from 0.6 to 1.2 per 1,000 US population (P for trend=.02). Similarly, the absolute number of visits increased 88%, from 300,000 (95% CI 209,000 to 392,000) in 1993 to 1994 to 564,000 (95% CI 423,000 to 705,000) in 2003 to 2004. Approximately 64% (95% CI 59% to 69%) of these patients were admitted to the hospital, a rate that remained constant throughout the 12-year period (P for trend=.73). Admission rates were significantly lower in the western region of the United States (48%; 95% CI 36% to 60% versus 76%; in the Northeast, 95% CI 68% to 84%). Patient characteristics and ED management did not materially differ by admission status. In a multivariate model, congestive heart failure was the only predictor of admission but accounted for only 14% of admissions. From 1993 to 2004, the population-adjusted rate of ED visits for atrial fibrillation increased, whereas the proportion admitted to the hospital remained stable. Patient characteristics and ED management were similar regardless of admission status, and there were relatively few predictors of admission.