Emergency Department Visits for Acetaminophen Overdose: a Canadian Population-based Epidemiologic Study (1997-2002)

Objective: 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.

Methods: 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.

Results: 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.

Conclusions: 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.