Retrospective Analysis of Long-term Impact of COVID-19 Pandemic on Mammographic Breast Cancer Screening

To determine whether the initial decrease in mammographic breast cancer screening (MBCS) rates with the corona virus disease of 2019 (COVID-19) pandemic persisted in the postpandemic times and quantify the impact of health care disparities.

This retrospective study analyzed data from March 1, 2017 to March 31, 2023 to assess annual MBCS among eligible women (40-75 years) in the Mayo Clinic system. The study period was divided into 4 phases: pre-COVID-19 (2017-2020), early pandemic (2020-2021), mid-pandemic (2021-2022), and late pandemic (2022-2023). Mixed-effects poisson regression estimated incidence rate ratios (IRR), and difference-in-differences assessed temporal trends.

The cohort included 239,804 women with a median age of 57 years, of whom 34.9% resided in rural counties. By race, 92% were White, 3.1% Black, 0.4% American Indians, 0.1% Native Hawaiians, 3% Asian, and 1.3% others. Compared with the pre-COVID-19 period, there was a significant decrease in MBCS rate in the early pandemic (IRR=0.891, P<.001), and though the rate improved in the mid-pandemic and late pandemic periods, they remained below the prepandemic level (IRR=0.941, P<.001; IRR=0.922, P<.001, respectively). Rural counties had lower MBCS rates compared with urban (IRR = 0.914, P<.001). Compared to White race, other races had lower MBCS rates with the Black race having the lowest (IRR=0.692, P<.001). Difference-in-differences analysis revealed that the relative gap between MBCS rates in minority/rural groups did not significantly widen or narrow during the pandemic.

The COVID-19 pandemic was associated with sustained declines in MBCS through early 2023, disproportionately affecting vulnerable populations but did not widen pre-existing disparities, highlighting the benefits of targeted interventions.