Increased Cancer Screening for Low-income Adults Under the Affordable Care Act Medicaid Expansion

BACKGROUND: We tested whether Medicaid expansion under the Affordable care Act was associated with increased screening for cervical, breast, and colorectal cancer among low-income adults. METHODS: We analyzed Behavioral Risk Factor Surveillance System data, identifying 2012 as preexpansion and 2016 as postexpansion (2014 was treated as a wash-out, and 2013 and 2015 had missing screening data from most states). States (including District of Columbia) either expanded Medicaid in 2014 (n=28) or not (n=18); five states that expanded after 2014 were excluded. Participants included low-income adults aged 18-64 without dependent children. A difference-in-difference approach tested whether expansion was significantly associated with screening, controlling for time, state effects, age, sex, race/ethnicity, education, and urban/rural population. For comparison, we also conducted analyses among the low-income Medicare (aged 65 and above) population, and a higher income population. RESULTS: There was a significant expansion effect for women aged 18-64 for cervical cancer screening (N=29,059; odds ratio, 1.04; 95% confidence interval, 1.01-1.08), and for adults 50-64 for colorectal cancer screening (N=32,290; odds ratio, 1.12; 95% confidence interval, 1.03-1.22). Effects for mammography for women aged 40-64, or aged 50-64, were not significant. As expected, there were no significant improvements associated with expansion among the Medicare population, or among a population ineligible due to higher income. CONCLUSIONS: Medicaid expansion under the Affordable Care Act was associated with increased screening for cervical and colorectal cancer for low-income adults. It will be important to monitor possible adverse cancer outcomes in nonexpansion states among vulnerable populations over time.