Part D Subsidies Can Help Reduce Racial Disparities in Breast Cancer Treatment Persistence

A recent study has found that low-income subsidies under the Medicare Part D program can help improve rates of persistence and adherence to breast cancer therapies among Hispanic and black women.

Prior studies have indicated that nonadherence and nonpersistence are higher in black and lower-income women receiving hormonal therapy for breast cancer. A group of researchers hypothesized that the high cost of therapy may be a significant factor impeding the continuation of treatment, and conducted a study to assess the impact of financial subsidies provided under Medicare Part D on racial and ethnic disparities in adherence and persistence. The findings were published in the Journal of Clinical Oncology.

Medicare Part D provides pharmaceutical coverage, but beneficiaries are responsible for premiums, deductibles, copays, and costs within a coverage gap. However, its Low-Income Subsidy program provides either partial or full subsidies for patients who cannot afford these additional costs, which could potentially lower rates of nonpersistence and nonadherence.

Using a Medicare claims database, the researchers identified 25,511 patients who had received hormonal therapy for breast cancer and classified them by race/ethnicity and subsidy status. They also calculated the rates of nonpersistence, defined as 90 consecutive days without a claim for a hormonal therapy prescription, and nonadherence, defined as a medication possession rate of less than 80%.

They found that 27% of the study cohort, but 77% of the Hispanic women and 70% of the black women, received the low-income subsidy. Hispanic and black women were more likely to continue treatment throughout the study period—69% of black patients and 70% of Hispanic patients were persistent after 2 years, compared with 61% of white patients.

Regardless of race or ethnicity, women receiving subsidies had higher rates of persistence than the women who did not, who “were 60% to 200% more likely to discontinue hormonal therapy in the first 35 months compared with the Low-Income Subsidy recipients of the same race or ethnicity,” according to the authors. Disparities were evident among women on unsubsidized healthcare; the time it took for one-quarter to discontinue therapy was 12 months for white women, 10 months for Hispanic women, and 9 months for black women.

While rates of adherence were similar among white, Hispanic, and black women, the researchers again observed significant disparities between the subsidized and unsubsidized groups of patients. Women receiving subsidies were 30% more likely to be adherent than those who did not get the subsidies, and the probability of adherence was 2.7% lower for unsubsidized women while they were in the Medicare coverage gap.

These results, according to the authors, point to the importance of subsidies as a tool for increasing adherence and persistence and thus improving cancer outcomes for minority and low-income women. In a novel finding, the subsidies eliminated or even reversed the racial and ethnic disparities in persistence observed among unsubsidized women.

The authors concluded that more policy efforts like the subsidies are needed to expand access and “improve equity in cancer outcomes.”

“Given the high costs of oral oncologic and supportive medications, the impact on disparities of other initiatives to reduce out-of-pocket costs deserves urgent study,” they wrote.