Characterizing the clinical subgroups of individuals who present to the emergency department for alcohol-related harms in Ontario, Canada: A latent class analysis.

Alcohol-related emergency department (ED) visits are common and associated with adverse clinical outcomes, including premature mortality. This population-based retrospective cohort study identified clinically distinct subgroups of individuals who experience alcohol-related ED visits and characterized differences in the risk of adverse outcomes between them. 73,658 individuals who experienced an alcohol-related ED visit in Ontario, Canada between 2017 and 2018 were identified. Latent class analysis (LCA) revealed five clinically distinct subgroups within the overall cohort. These subgroups followed a severity gradient from low-frequency service use for acute intoxication to high-frequency service use for alcohol use disorder (AUD) and related comorbidities. Relative to those presenting for acute intoxication, those presenting for AUD and comorbidities had a much higher risk of hospital admission (adjusted odds ratio [aOR]: 8.26, 95 % confidence interval [CI]: 7.81-8.75) and post-discharge mortality (adjusted hazard ratio [aHR]: 3.07, 95 % CI: 2.81-3.37). There was a subgroup of individuals with a history of high frequency alcohol-related health service use who were at the highest risk of experiencing another alcohol-related ED visit after the index event (aHR: 4.76, 95 % CI: 4.55-4.99). Individuals who experience alcohol-related ED visits are not a homogenous population, but a constellation of subgroups with different clinical characteristics and risk of adverse outcomes.