The effect of Medicaid expansion on prescriptions for breast cancer hormonal therapy medications

Health Serv Res. 2020 Jun;55(3):399-410. doi: 10.1111/1475-6773.13289. Epub 2020 Apr 17.


Objective: To quantify the effects of the Affordable Care Act Medicaid expansion on prescriptions for effective breast cancer hormonal therapies (tamoxifen and aromatase inhibitors) among Medicaid enrollees.

Data source/study setting: Medicaid State Drug Utilization Database (SDUD) 2011-2018, comprising the universe of outpatient prescription medications covered under the Medicaid program.

Study design: Differences-in-differences and event-study linear models compare population rates of tamoxifen and aromatase inhibitor (anastrozole, exemestane, and letrozole) use in expansion and nonexpansion states, controlling for population characteristics, state, and time.

Principal findings: Relative to nonexpansion states, Medicaid-financed hormonal therapy prescriptions increased by 27.2 per 100 000 nonelderly women in a state. This implies a 28.8 percent increase from the pre-expansion mean of 94.2 per 100 000 nonelderly women in expansion states. The event-study model reveals no evidence of differential pretrends in expansion and nonexpansion states and suggests use grew to 40 or more prescriptions per 100 000 nonelderly women 3-5 years postexpansion.

Conclusions: Medicaid expansion may have had a meaningful impact on the ability of lower-income women to access effective hormonal therapies used to treat breast cancer.

Keywords: Medicaid; breast cancer; differences-in-differences; prescription medications; public insurance.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Antineoplastic Agents, Hormonal / administration & dosage
  • Antineoplastic Agents, Hormonal / therapeutic use*
  • Breast Neoplasms / drug therapy*
  • Female
  • Humans
  • Male
  • Medicaid / legislation & jurisprudence
  • Medicaid / statistics & numerical data*
  • Middle Aged
  • Patient Protection and Affordable Care Act / legislation & jurisprudence
  • Sex Factors
  • United States


  • Antineoplastic Agents, Hormonal