Racial and Gender Disparities In Medication Nonadherence: A Pre/Post Medicare Part D Comparison

Background and Purpose: Pharmaceuticals are an increasingly essential part of treatment for chronic conditions among the older adult population. However, cost continues to be a barrier to medication access and can prevent older individuals from maintaining compliance. While gender and racial disparities in cost-related medication nonadherence (CRN) prior to the Medicare prescription drug benefit (Part D) existed, studies have not examined the prevalence of racial and gender disparities in CRN since the policy's enactment. The objectives of this longitudinal study were to determine: 1) whether racial and gender disparities in CRN have changed since the implementation of Medicare Part D; and 2) whether socioeconomic status, health status, and prescription insurance coverage directly and indirectly effect the relationship between race and gender and CRN over time.

Methods: This study utilizes secondary data from the 2004 and 2006 waves of the Health and Retirement Study (HRS) and data from the 2005 and 2007 waves of the Prescription Drug Study (PDS), a subsample of the HRS, to evaluate changes in CRN before and after Medicare Part D. The analytic sample consisted of 3,171 respondents age 65 and older who were Medicare-eligible and taking at least one prescribed medication. The outcome variable of interest was CRN, which included not filling, stopping, or skipping doses of a prescription because of cost. The main predictors were race (Black and White) and gender (male and female). Covariates included demographics, socioeconomic status, health status, and type of prescription drug coverage. The analysis was conducted using mixed-effects logistic regression models.

Results: Results indicated that older Blacks and females were significantly more likely to report CRN both before and after Medicare Part D compared to older Whites and men. While the rate of CRN for females significantly decreased over time in comparison to males, there was no change in the rate for Blacks relative to Whites. The introduction of variables related to socioeconomic status, health status, and prescription insurance coverage had little mediating effect on these findings. Health status, annual income, and prescription insurance coverage, however, had a direct effect on CRN before and after Medicare Part D.

Conclusions and Implications: Racial and gender disparities in CRN continue to persist despite the presence of Medicare Part D. CRN for older Blacks in comparison to older Whites did not change over time. However, older females experienced a significantly greater decline in CRN over time as compared to older men. This suggests that Medicare Part D may be more effective in addressing gender disparities in CRN than racial differentials. Furthermore, despite the presence of a drug benefit under Medicare, socioeconomic status, health status, and prescription insurance coverage continue to impact CRN. 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 can help substantiate the need to account for race and gender when evaluating policy alternatives in order to promote more equitable access to medications.