Epidemiology of adrenal insufficiency: A nationwide study of hospitalizations in Taiwan from 1996 to 2008

BackgroundAdrenal insufficiency (AI) is an uncommon but life-threatening disorder if it progresses to adrenal crisis. The nationwide trend of AI epidemiology in Taiwan has been infrequently reported.MethodsBased on complete hospitalization datasets from the National Health Insurance Research Database, the trend of the annual incidence of AI from 1996 to 2008 in Taiwan was retrospectively analyzed. Special attention was paid to age-specific incidence, contributing factors as well as comorbidity at the time of AI diagnosis.ResultsOf the existing 35,884,231 hospitalization records, there were 52,660 with AI diagnosis in 32,085 patients (15,914 women and 16,163 men). The annual incidence of AI increased over time from 6.4/105 (n = 1280) in 1996 to 15.2/105 (n = 3494) in 2008. Nearly four-fifths (77%, n = 24,688) of the patients were aged at least 60 years at the time of their first AI diagnosis. The increase of the annual incidence of AI during the study period was largely attributed to disease prevalence in patients aged 60 years and over, with the most marked increase in the population aged 80 years of age from 51.1/105 in 1996 to 179.9/105 in 2008. Most patients with newly diagnosed AI were treated at internal medicine wards (81.1%, n = 26,032), at academic medical centers (51.9%, n = 16,648) and in southern Taiwan (54%, n = 17,334). The most common comorbidity was pneumonia (6.4%, n = 2051), followed by urinary tract infection (6.4%, n = 2049), diabetes mellitus (6.2%, n = 1985), electrolyte imbalance (4.8%, n = 1551), and chronic obstructive pulmonary disease (4.5%, n = 1428).ConclusionThe annual incidence of AI in Taiwan had continuously increased in recent years, and elderly patients accounted for the majority of the increase. In the face of an increasingly aging population, Taiwanese physicians should pay more attention to this easily overlooked disease.