Abstract B011: Changes in prescriptions for breast cancer medications after Medicaid expansion
Authors: Maclean Catherine , Halpern Michael T. , Hill Steven C. , Pesko Michael 
Published: August 2020

Abstract
As of summer 2018, 34 states have expanded Medicaid eligibility under the Affordable Care Act. While the Medicaid expansions decreased rates of being uninsured among women with breast cancer and increased early breast cancer detection, it is unknown whether expansions increased receipt of medications used to prevent and treat breast cancer. This study examines differences over time in receipt of two types of breast cancer hormonal therapies (tamoxifen and aromatase inhibitors) and associated payments for these medications in states that did vs. did not expand Medicaid during the period 2011-2017. The study's data source is the Medicaid State Drug Utilization Database (SDUD). This data set, compiled by the Centers for Medicaid and Medicare (CMS), is administrative data submitted by state Medicaid programs. The data comprise outpatient prescription medications that are covered under the Medicaid Drug Rebate Program for which Medicaid serves as a third-party payer; this includes aggregate numbers of prescriptions and associated payments for individuals enrolled in both fee for service and managed-care Medicaid programs. Both branded and generic prescriptions for three aromatase inhibitors (anastrozole, exemestane, and letrozole) were included in the study's analyses. Analyses used differences-in-differences and event study models (controlling for state characteristics) to compare changes in Medicaid expansion states to changes in nonexpansion states before vs. after expansion. Initial regression analyses indicate that prescriptions for all hormonal therapy medications increased by 22% (p&lt;0.05) and prescriptions for aromatase inhibitors (branded and generics combined) increased by 26% (p&lt;0.05) in expansion states relative to nonexpansion states. While prescriptions for tamoxifen and for generic aromatase inhibitors alone also increased in expansion states, these changes were not statistically significant. Post-expansion, both total payments and Medicaid payments for all hormonal therapies increased by 13% (p&lt;0.01) in expansion states relative to nonexpansion states. The similar increases for total and Medicaid payments suggest that state Medicaid programs, not patients, financed the increased hormonal therapy prescription payments. Our findings indicate that states that expanded Medicaid with the ACA experienced increased prescriptions for breast cancer hormonal therapies relative to states that did not expand Medicaid; this effect of Medicaid expansion increased over time. The increased prescriptions were financed by Medicaid, not by patients.
Citation Format: Catherine Maclean, Michael T. Halpern, Steven C. Hill, Michael Pesko. Changes in prescriptions for breast cancer medications after Medicaid expansion [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B011.