BackgroundOut-of-hospital cardiac arrest (OHCA) remains a prominent medical concern worldwide. Epidemiological metrics and trends over time for OHCA cases in Canada are not well-defined. This study evaluated geographical differences in the incidence and outcomes of OHCA patients admitted to hospitals across Canada from 2013 to 2017. MethodsThis population-based retrospective cohort study included 10,492 non-traumatic OHCA patients aged 2-85 years (66% male) who were admitted to an acute care hospital in any Canadian province or territory (excluding Quebec) between 2013 and 2017. Overall age- and sex-standardized incidence measures (per 100,000 population per year) were calculated through direct standardization to the 2016 Canadian population. Temporal trends in incidence and survival to hospital discharge were evaluated. ResultsThe overall age- and sex-standardized incidence of OHCA patients admitted to the hospital was 8.3 per 100,000 population per year, which did not significantly change from 2013 to 2017 (incidence rate ratio: 1.01, 95% confidence interval: 0.99-1.02). Incidence was highest in British Columbia (9.2), Manitoba (9.0), and Nova Scotia (9.0), and lowest in New Brunswick (6.5), Prince Edward Island (6.8), and Saskatchewan (7.5). The proportion of OHCA patients who survived to hospital discharge was highest in Prince Edward Island (57%) and lowest in Ontario (38%). No significant trend in survival to hospital discharge rates was observed from 2013 (43%) to 2017 (42%; p=0.86). ConclusionsThe age- and sex-standardized incidence and survival outcomes of OHCA patients admitted to the hospital were stable from 2013 to 2017 in Canada, with considerable variation noted across geographical regions.Introduction