Changes in Female Cancer Diagnostic Billing Rates over the COVID-19 Period in the Ontario Health Insurance Plan

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.