Changes in female cancer diagnostic billing rates over the COVID-19 period in the Ontario Health Insurance Plan.

BACKGROUND

The initial response to coronavirus disease 2019 (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.

OBJECTIVES

To compare annual billing prevalence and incidence rates of female cancers during the COVID-19 period (2020-2022) to pre-COVID-19 levels (2015-2019).

DESIGN

Retrospective analysis of aggregated claims data for female cancer diagnostic codes from the Ontario Health Insurance Plan (OHIP).

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 cancers 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 cancer types (108.3/100k, 123.7/100k, 5.2/100k, and 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.