RT Journal Article SR Electronic T1 Clearing the surgical backlog caused by COVID-19 in Ontario: a time series modelling study JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E1347 OP E1356 DO 10.1503/cmaj.201521 VO 192 IS 44 A1 Jonathan Wang A1 Saba Vahid A1 Maria Eberg A1 Shannon Milroy A1 John Milkovich A1 Frances C. Wright A1 Amber Hunter A1 Ryan Kalladeen A1 Claudia Zanchetta A1 Harindra C. Wijeysundera A1 Jonathan Irish YR 2020 UL http://www.cmaj.ca/content/192/44/E1347.abstract AB BACKGROUND: To mitigate the effects of coronavirus disease 2019 (COVID-19), jurisdictions worldwide ramped down nonemergent surgeries, creating a global surgical backlog. We sought to estimate the size of the nonemergent surgical backlog during COVID-19 in Ontario, Canada, and the time and resources required to clear the backlog.METHODS: We used 6 Ontario or Canadian population administrative sources to obtain data covering part or all of the period between Jan. 1, 2017, and June 13, 2020, on historical volumes and operating room throughput distributions by surgery type and region, and lengths of stay in ward and intensive care unit (ICU) beds. We used time series forecasting, queuing models and probabilistic sensitivity analysis to estimate the size of the backlog and clearance time for a +10% (+1 day per week at 50% capacity) surge scenario.RESULTS: Between Mar. 15 and June 13, 2020, the estimated backlog in Ontario was 148 364 surgeries (95% prediction interval 124 508–174 589), an average weekly increase of 11 413 surgeries. Estimated backlog clearance time is 84 weeks (95% confidence interval [CI] 46–145), with an estimated weekly throughput of 717 patients (95% CI 326–1367) requiring 719 operating room hours (95% CI 431–1038), 265 ward beds (95% CI 87–678) and 9 ICU beds (95% CI 4–20) per week.INTERPRETATION: The magnitude of the surgical backlog from COVID-19 raises serious implications for the recovery phase in Ontario. Our framework for modelling surgical backlog recovery can be adapted to other jurisdictions, using local data to assist with planning.