Emergency department visits for acetaminophen overdose: a Canadian population-based epidemiologic study (1997–2002)

Abstract

We describe the epidemiology of emergency department (ED) visits for acetaminophen overdose in a large Canadian health region, with a focus on sociodemographic risk factors and temporal trends. Patients presenting to an ED in the Calgary Health Region (population approximately 1.1 million) for acetaminophen overdose between 1997 and 2002 were identified using regional administrative data. A total of 2699 patients made 3015 ED visits for acetaminophen overdose between 1997 and 2002, corresponding to an age- and sex-adjusted incidence of 45.7 per 100,000 population. Alcohol-related disorders were common (19%) and overdose rates were higher in females, younger patients, Aboriginals and social assistance recipients. The incidence decreased from 52.6 per 100,000 in 1997 to 35.1 per 100,000 in 2002 (34% relative reduction; p < 0.0005). When classified according to suicidal intent, the rates of intentional and unintentional overdose (69% and 25% of all overdoses, respectively) showed similar temporal trends. A marked seasonality was observed, with a peak in spring and early summer. ED visit rates for acetaminophen overdose fell between 1997 and 2002. High-risk groups, including young females and marginalized populations, may benefit from preventive and educational initiatives.