OBJECTIVES : Limited evidence exists of the association of low-income subsidy/dual-eligibility status (LIS/DE) and disability with high-risk medication (HRM) use among Medicare Part D beneficiaries with different drug plans. Using the Pharmacy Quality Alliance HRM measure, this study examined the relationship between: 1) LIS/DE and HRM use; and 2) disability and HRM use in Medicare Advantage Prescription Drug Plan (MA-PD) and stand-alone Prescription Drug Plan (PDP) beneficiaries.

METHODS : This retrospective cross-sectional study used a 5% national sample of 2013 Medicare administrative claims data to create two groups of beneficiaries aged ≥65 years who were continuously enrolled in a MA-PD or PDP. Beneficiaries with ≥2 prescriptions for the same HRM during 2013 were identified. Multivariable generalized linear mixed models were used to assess the association of: 1) LIS/DE and HRM use; and 2) disability and HRM use, after adjusting for health plan effect and patient-level characteristics in MA-PDs and PDPs.

RESULTS : A total of 520,019 MA-PD and 881,264 PDP beneficiaries met the study criteria. Of these, 88,693 MA-PD and 213,096 PDP beneficiaries were LIS/DE, while 48,997 MA-PD and 83,593 PDP were disabled. LIS/DE beneficiaries had a higher proportion of HRM users compared to non-LIS/DE beneficiaries (MA-PD 13.3% versus 9.7%, p<0.001; PDP 17.1% versus 13.2%, p<0.001). Disabled beneficiaries had a higher proportion of HRM users compared to non-disabled beneficiaries (MA-PD 17.0% versus 9.6%, p<0.001; PDP 22.9% versus 13.2%, p<0.001). In multivariable analyses, LIS/DE and disability were associated with HRM use among both MA-PD (LIS/DE odds ratio [OR]=1.07; 95% confidence interval [CI]=1.04-1.10; disability OR=1.38; 95% CI=1.34-1.42) and PDP beneficiaries (LIS/DE OR=1.14; 95% CI=1.12-1.16; disability OR=1.37; 95% CI=1.34-1.40).

CONCLUSIONS : LIS/DE and disability were associated with higher HRM use in both MA-PD and PDP beneficiaries, even when controlling for health plans, underscoring the importance of considering these factors when assessing health plan performance on HRM measures.