Rising out-of-hospital mortality in Canada during 2020‒2022: A striking impact observed among young adults

Objective: Out-of-hospital mortality rates surged during the early COVID-19 pandemic. While expecting a return to pre-pandemic levels, the evolving patterns of out-of-hospital mortality in Canada remain uncertain. We investigated whether these rates returned to pre-pandemic levels. Methods: This retrospective study, employing linked administrative data, analyzed out-of-hospital mortality trends among adult residents in Ontario, Alberta, and Nova Scotia. Interrupted time series analysis assessed trends in age- and sex-standardized rates/100,000/quarter during pre-pandemic (April 2014–March 2020) and pandemic periods (April 2020–March 2022), while considering April to June 2020 as the pandemic onset period. Crude mortality rates were also examined, stratified by sex and age groups. Results: Pre-pandemic, Ontario’s standardized out-of-hospital mortality rates were rising, while Alberta’s and Nova Scotia’s remained stable. At the pandemic onset, all provinces experienced significant increases in standardized out-of-hospital mortality rates/100,000 (Ontario: β 14.6, 95% CI [3.97, 25.22]; Alberta: 21.3, 95% CI [9.26, 33.34]; Nova Scotia: 10.5, 95% CI [1.06, 19.88]). During the pandemic, standardized out-of-hospital mortality rates/100,000/quarter remained above pre-pandemic levels, with no significant departure from the increased pandemic onset levels (Ontario: − 1.6, 95% CI [− 3.63, 0.52]; Alberta: 0.45, 95% CI [− 1.47, 2.36]; Nova Scotia: − 0.06, 95% CI [− 2.18, 2.06]). Crude out-of-hospital mortality rates increased most prominently among individuals aged 18 to 45 in Alberta and Ontario, and among males across all provinces. Conclusion: The sustained increase in out-of-hospital mortality, observed from the pandemic’s onset, spanning more than 2 years, potentially suggests its persistent direct and indirect effects on population health in Canada.