Medicaid Expansions and Cancer Screening for Low-Income Women

Morbidity and mortality from both breast and cervical cancer can be reduced through screening, leading to early detection and treatment. While mortality rates have fallen over recent decades due to improved screening and treatment, these benefits are not distributed equally across the population. There are substantial disparities in breast and cervical cancer diagnosis and outcomes in the US by insurance and socioeconomic status. Despite the existence of programs aimed at screening underserved women many eligible women are not reached. Medicaid coverage for low-income women may play an important role in ensuring access to screening. Recent research has shown that Medicaid expansions to non-elderly adults are associated with lower mortality and improved access, but more evidence is needed on the precise mechanisms for improvements in overall health and the effects on particular types of care, including preventive care. Cancer screening is a key indicator of preventive care utilization and patient investment in health.

This study examines how expansions of Medicaid eligibility to non-elderly adults impact breast and cervical cancer screening among low-income women. We use data from the Women’s Health Module of the Behavioral Risk Factor Surveillance System from 1996 to 2010 to investigate the effect of substantial Medicaid eligibility expansions to parents and childless adults in New York, Maine, and Arizona in 2001 and 2002. Primary outcomes of interest are whether women in the relevant guideline consistent age range reported receiving a mammogram or Pap test in the previous year. Other screening intervals are investigated in secondary analyses. Expansion states are compared to a set of neighboring control states in a difference-in-differences  framework. Regression models control for age, race, marital status, education, income, and employment, as well as state and year fixed effects and interactions between the year and each treatment and control state pairing. We consider changes in screening for all women in the expansion states as well as women with household income under 150% of the federal poverty level who were likely to be in the eligible population post-expansion.  In addition, we explore the role of other determinants of access, such as having a regular doctor, on screening outcomes.

Our results indicate that cervical cancer screening increased significantly among low-income women in expansion states relative to control states after increases in Medicaid eligibility. While point estimates of the effect of expansions on breast cancer screening are positive, they are not statistically significant. Differences in the effects on the two types of screening may be due to differences in the complexity of the test or the populations recommended to receive each. Nonetheless, we find that expansions improved preventive care along a key measure that is important for early cancer detection and prevention of cancer morbidity and mortality. The results suggest that larger expansions of Medicaid under the Affordable Care Act may be expected to have positive effects on preventive healthcare for women. Coverage expansions seem to be effective at increasing at least some types of cancer screening and targeting populations that have traditionally been underserved.