%0 Journal Article %A Teresa C.O. Tsui %A Seraphine Zeitouny %A Karen E. Bremner %A Douglas C. Cheung %A Carol Mulder %A Ruth Croxford %A Lisa Del Giudice %A Lauren Lapointe-Shaw %A Andrew Mendlowitz %A William W.L. Wong %A Nathan Perlis %A Beate Sander %A Paulos Teckle %A George Tomlinson %A Jennifer D. Walker %A Kamil Malikov %A Kimberlyn M. McGrail %A Stuart Peacock %A Girish S. Kulkarni %A Reka E. Pataky %A Murray D. Krahn %T Initial health care costs for COVID-19 in British Columbia and Ontario, Canada: an interprovincial population-based cohort study %D 2022 %R 10.9778/cmajo.20210328 %J CMAJ Open %P E818-E830 %V 10 %N 3 %X Background: COVID-19 imposed substantial health and economic burdens. Comprehensive population-based estimates of health care costs for COVID-19 are essential for planning and policy evaluation. We estimated publicly funded health care costs in 2 Canadian provinces during the pandemic’s first wave.Methods: In this historical cohort study, we linked patients with their first positive SARS-CoV-2 test result by June 30, 2020, in 2 Canadian provinces (British Columbia and Ontario) to health care administrative databases and matched to negative or untested controls. We stratified patients by highest level of initial care: community, long-term care, hospital (without admission to the intensive care unit [ICU]) and ICU. Mean publicly funded health care costs for patients and controls, mean net (attributable to COVID-19) costs and total costs were estimated from 30 days before to 120 days after the index date, or to July 31, 2020, in 30-day periods for patients still being followed by the start of each period.Results: We identified 2465 matched people with a positive test result for SARS-CoV-2 in BC and 28 893 in Ontario. Mean age was 53.4 (standard deviation [SD] 21.8) years (BC) and 53.7 (SD 22.7) years (Ontario); 55.7% (BC) and 56.1% (Ontario) were female. Net costs in the first 30 days after the index date were $22 010 (95% confidence interval [CI] 19 512 to 24 509) and $15 750 (95% CI 15 354 to 16 147) for patients admitted to hospital, and $65 828 (95% CI 58 535 to 73 122) and $56 088 (95% CI 53 721 to 58 455) for ICU patients in BC and Ontario, respectively. In the community and long-term care settings, net costs were near 0. Total costs for all people, from 30 days before to 30 days after the index date, were $22 128 330 (BC) and $175 778 210 (Ontario).Interpretation: During the first wave, we found that mean costs attributable to COVID-19 were highest for patients with ICU admission and higher in BC than Ontario. Reducing the number of people who acquire COVID-19 and severity of illness are required to mitigate the economic impact of COVID-19. %U https://www.cmajopen.ca/content/cmajo/10/3/E818.full.pdf