Previous studies on atrial fibrillation (AF) epidemiology have used various case definitions for AF, but the effect of location of diagnosis on the apparent epidemiology of AF is unknown.
Population-based study of 46,440 consecutive patients with newly diagnosed AF in Alberta, Canada, from 2000 to 2005.
Of adults newly diagnosed with AF (52.8% men, median 73 years), 51.8% were first diagnosed in hospital, 19.2% in emergency department (ED), and 29.0% in outpatient clinics. Prevalence of AF increased from 613 per 100,000 to 1,148 per 100,000 population over 5 years; however, the age- and sex-standardized incidence of AF remained relatively stable (350 per 100,000 in 2000 and 352 per 100,000 in 2005). The proportion of AF cases diagnosed in hospital declined 21% between 2000 and 2005, whereas the proportion of cases diagnosed in the outpatient setting rose by 50% (P