Louanne Bakk, PhD

2012
Gender and racial disparities in cost-related medication nonadherence: The effect of Medicare Part D and factors impacting compliance among older women and Black Americans

The purpose of this dissertation is to better understand how cost-related medication nonadherence (CRN) has been impacted by the implementation of Medicare Part D. CRN can include not filling, stopping, or skipping doses of a prescription because of cost. While gender and racial disparities in CNR prior to Medicare Part D clearly existed, studies have not examined whether differences in CRN persist since the implementation of Medicare Part D. Longitudinal and cross-sectional analyses were conducted using data from the Health and Retirement Study (HRS) and the Prescription Drug Study, a subsample of the HRS, to examine racial and gender differences in CRN before and after Medicare Part D and factors associated with the benefit that can impact adherence.

This study addressed the following questions:

  • To what extent do racial and gender disparities in CRN exist since the implementation of Medicare Part D?
  • Do the Medicare Part D Low-Income Subsidy (LIS), coverage gap, and restrictions directly and indirectly affect the relationship between race, gender, and CRN?
  • How do socioeconomic and health status directly and indirectly affect relationships between race, gender, and CRN?

The results suggested that older Black Americans and females are more likely to report CRN before and after Medicare Part D than older Whites and males. Applying for the LIS increased the risk of CRN and mediated gender differences. Racial disparities in CRN appeared to be driven by having a Medicare Part D plan with a gap in coverage. Poorer health, lower annual income, and experiencing the coverage gap and restrictions increased the likelihood of CRN.

The findings provided important insights into Medicare Part D’s effectiveness in eliminating racial and gender differentials in CRN. Despite the presence of a drug benefit under Medicare, racial and gender disparities in CRN persisted.

Understanding how Medicare Part D has affected adherence can help social work practitioners recognize that clients may need additional resources and assistance in order to avoid CRN. Additionally, findings helped substantiate the need to account for race and gender when evaluating policy alternatives in order to promote more equitable access to medications.