Changes in Breast and Colorectal Cancer Screening After Medicaid Expansion Under the Affordable Care Act

Introduction Medicaid expansions following the Affordable Care Act have improved insurance coverage in low-income adults, but little is known about its impact on cancer screening. This study examined associations between Medicaid expansion timing and colorectal cancer (CRC) and breast cancer (BC) screening. Methods Up-to-date and past 2-year CRC ( n =95,400) and BC (women, n =43,279) screening prevalence were computed among low-income respondents aged 50–64 years in 2012, 2014, and 2016 Behavioral Risk Factor Surveillance System data. Respondents were grouped according to Medicaid expansion timing as: very early ([VE] six states expanding March 1, 2010–April 14, 2011), early (21 states expanding January 1, 2014–August 15, 2014), late (five states expanding January 1, 2015–July 1, 2016), and non-expansion states (19 states). Absolute adjusted difference-in-differences (aDDs) were computed in 2018–2019 (ref, non-expansion states). Results Between 2012 and 2016, absolute up-to-date CRC screening increased by 8.8%, 2.9%, 2.4%, and 3.8% among low-income adults in VE, early, late, and non-expansion states, respectively. Past 2–year CRC screening increased by 8.0% in VE and 2.8% in non-expansion states, with an aDD of 4.9% ( p =0.041). In 2012–2016, up-to-date BC screening increased by 5.1%, 4.9%, and 3.7% among low-income women in VE, early, and non-expansion states, respectively, but aDDs were not statistically significant. Conclusions Prevalence of CRC and BC screening among low-income adults rose in Medicaid expansion states, though increases were significantly higher than those in non-expansion states only for recent CRC screening in VE expansion states. Large-scale improvements in cancer screening may take several years following expansion in access to care.