Background and Objectives The initial response to COVID-19 in Ontario included suspension of cancer screening programs and deferral of diagnostic procedures and many treatments. Although the short-term impact of these measures on female cancers is well documented, few studies have assessed the mid- to long-term impacts. We conducted an analysis of Ontario Health Insurance Program (OHIP) claims for female cancer diagnostic codes by comparing annual billing prevalence and incidence rates during the COVID-19 period (2020-2022) to pre-COVID-19 levels (2015-2019). Methods Linear regression analysis was used to fit pre-COVID-19 (2015-2019) data for each OHIP billing code and extrapolate counterfactual values for the years of 2020-2022. Excess billing rates were calculated as the difference between projected and actual rates for each year. Results In 2020, OHIP billing prevalence rates for cervical, breast, uterine and ovarian cancer decreased relative to projected values for that year by -50.7/100k, -13.9/100k, -3.5/100k and -3.8/100k, respectively. The reverse was observed in 2021 with rate increases of 47.8/100k, 59.1/100k, 2.5/100k and 3.7/100k, respectively. In 2022, the excesses were further amplified, especially for cervical and breast cancers (111.2/100k and 78.67/100k, respectively). The net excess patient billing rate for 2020-2022 was largely positive for all female cancers (108.3/100k, 123.7/100k, 5.2/100k, 1.8/100k, respectively). Analysis of billing incidence rates showed similar trends. Conclusion The expected female cancer billing rate decreases in 2020 were followed by large increases in 2021 and 2022, resulting in a cumulative excess during the COVID-19 period. Further research is required to assess the nature of these changes.

Alon D. Altman has been employed and/or served in a leadership position for Doctors MB, GOC, and CCMB PT committee, has served in a consultancy or advisory role for AstraZeneca, Eisai, Abbvie, Merck and GSK, and has received research funding from Merck, Pfizer AstraZeneca, Clovis, and CCMB Foundation. Christine Brezden-Masley has received honoraria from and served in a consultancy or advisory role for Astellas, Amgen, AstraZeneca, Beigene, Gilead Sciences, Pfizer, Novartis, Eli Lilly, Merck, BMS, Sanofi, and Knight Therapeutics, and has received research funding from Pfizer, AstraZeneca, Gilead Sciences, Eli Lilly, and Novartis. Nathalie LeVasseur has served in a leadership position for Provincial Breast Systemic, has received research funding and has served in a consultancy or advisory role for AstraZeneca, Eli Lilly, Gilead Sciences, Knight Therapeutics, Merck, Novartis, and Pfizer, and has received honoraria from AstraZeneca, Eli Lilly, Gilead Sciences, Knight Therapeutics, Merck, Novartis, and Pfizer. Ilidio Martins has no conflicts of interest to disclose. Deanna McLeod has no conflicts of interest to disclose. Amanda Selk has been employed and/or served in a leadership position for the Society of Canadian Colposcopists, International Society for the Study of Vulvovaginal Disease-North American Branch, and the International Federation of Colposcopy and Cervical Pathology, and has served in a consultancy or advisory role for Proctor and Gamble. Anna V. Tinker has received honoraria from and has served in a consultancy or advisory role for AstraZeneca, Merck, GSK, Eisai, and Abbvie, and has received research funding from AstraZeneca.

Funding for this article was provided through unrestricted educational grants from Eisai Limited (Canada) and The Society of Gynecologic Oncology of Canada (GOC). No discussion or viewing of review content was permitted with sponsors at any stage of manuscript development.

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All data analyzed in this study was aggregated Ontario claims data. No individual-level data nor any possibly identifying details were accessible to the study investigators.

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