Emergency department visits for gambling disorders after the legalization of single-event sports betting and rapid expansion of online gambling

Introduction — Online gambling and single-event sports betting have been legalized and expanded in North America. Although these changes have raised concerns over increased gambling-related harms, the impacts of gambling expansion are not well understood. This study examined changes in gambling-related emergency department visits after the legalization of single-event sports betting and privatized online gambling in Ontario, Canada.

Methods — This was a population-based study of all individuals in Ontario, Canada, aged ≥ 10 years, who were eligible for universal health coverage (N=17,353,640) between January 2012 and June 2025. An interrupted time series design estimated changes in the rates of emergency department visits for gambling disorders following online gambling liberalization in April 2022, overall and by age and sex.

Results — Over 14 years, there were 952 emergency department visits for gambling disorders from 757 unique individuals (mean [SD] age=41.8 [14.9] years; 72.0% male). The mean quarterly rates of emergency department visits for gambling disorders were 31.3% higher during the period after liberalization than before (1.28–1.68 per 1,000,000 individuals), with increases observed in males (1.81–2.63 per 1,000,000) but not females (0.77–0.74 per 1,000,000). Visits were stable pre-liberalization, showed no immediate change on implementation, but began to increase by 7% per quarter (Incidence rate ratio=1.07, 95% CI=1.04, 1.10). By the end of the study period (in April–June 2025), the rate of emergency department visits for gambling disorders was estimated to be 99.0% (incidence rate ratio=1.99, 95% CI=1.48–2.67) higher overall and 154.0% (incidence rate ratio=2.54, 95%=CI 1.15, 5.63) and 116.0% (incidence rate ratio=2.16, 95% CI=1.18, 3.95) higher in males aged 10–29 years and 30–44 years, respectively, than the expected rates without gambling market liberalization.

Conclusion — Online gambling expansion with legal single-event sports betting was associated with a doubling of rates of severe cases of gambling disorders, with increases occurring only in young men. Although such visits were rare, they may reflect broader population increases in gambling harms.