Trends in hospital activity, morbidity and case fatality related to atrial fibrillation in Scotland, 1986--1996.

AIMS Atrial fibrillation is a common and important cause of cardiovascular morbidity and mortality that may become more prevalent due to an ageing population and more prolonged exposure to predisposing cardiovascular disease states. This study examines recent trends in hospitalizations related to atrial fibrillation in Scotland. METHODS AND RESULTS Scotland (population 5.1 million) has a well described system for recording hospitalization data. All hospital discharges (and death) can be linked for each individual patient. We examined the period 1986--1996, during which time a total of 103,085 hospitalizations with a principal or secondary diagnosis of atrial fibrillation were recorded. The number of hospitalizations with a principal diagnosis of atrial fibrillation increased threefold from 1869 in 1986 to 5757 in 1996; the number with a secondary diagnosis rose from 3577 to 11,522. Similar increases were seen in the number of patients hospitalized, in those having a 'first-ever' hospitalization and in population hospitalization rates overall. The average age of patients rose, in men from 63.8 (SD 13.2) to 65.0 (13.2) years and in women from 72.2 (12.2) to 73.2 (11.4) years. The proportion of those aged >75 years rose from 33% to 35% in men and from 56% to 60% in women. Average length of stay and case fatality fell during this period, but, because of the overall increase in hospitalizations, atrial fibrillation contributed to a growing proportion of cardiovascular-related bed-days utilized (from 18% to 37% with atrial fibrillation coded in any diagnostic position). CONCLUSION The number of hospitalizations for atrial fibrillation has increased dramatically (two- to threefold) in recent years. These findings may be due to a real increase in atrial fibrillation prevalence, changing medical practice (e.g. coding or admission thresholds) or both. Consequently, the public health burden of atrial fibrillation is enormous. Moreover, the observed increase in atrial fibrillation-related hospital activity shows no sign of abating.