Factors associated with medication nonadherence among Medicare low-income subsidy beneficiaries with diabetes, hypertension, and/or heart failure.

BACKGROUND: Previous studies have documented factors influencing medication nonadherence among the Medicare population, but few studies have examined medication nonadherence among the Medicare low-income subsidy (LIS) population. Furthermore, little is known about the factors associated with nonadherence among this population, especially those with prevalent chronic conditions such as type 2 diabetes, hypertension, or heart failure. OBJECTIVE: To examine factors associated with the likelihood of medication nonadherence among Medicare LIS recipients with type 2 diabetes, hypertension, or heart failure. METHODS: This was a retrospective analysis of 2012-2013 Medicare Parts A, B, and D claims (most recent available for this research) linked to the Area Health Resources Files. Beneficiaries aged 65 years or older with continuous Medicare coverage and receiving any LIS were included. Individuals were categorized into full LIS or partial LIS groups. Nonadherence was determined by the proportion of days covered less than 80% for specified oral type 2 diabetes, hypertension, and heart failure medications, as defined by the Pharmacy Quality Alliance. A multivariate logistic regression was used to determine and compare individual-level and community-level characteristics associated with nonadherence among the entire study sample, the full LIS group, and the partial LIS group. RESULTS: The study sample included 505,771 Medicare beneficiaries, with 448,509 (88.7%) receiving full LIS and 57,262 (11.3%) receiving partial LIS. The proportion of individuals nonadherent was higher among the full LIS population (33.2%) than that of the partial LIS population (30.8%). Among the entire population, younger age was associated with nonadherence (OR = 0.98; 95% CI = 0.98-0.99). Men were more likely to be nonadherent than women (OR = 1.12; 95% CI = 1.11-1.14). Compared with non-Hispanic Whites, racial/ethnic minorities had higher nonadherence. Compared with beneficiaries who were non-Hispanic White, the ORs for those who were Black, Hispanic, Asian, and other were 1.41 (95% CI = 1.38-1.43), 1.58 (95% CI = 1.55-1.61), 1.08 (95% CI = 1.05-1.11), and 1.63 (95% CI = 1.56-1.70), respectively. There were higher nonadherence rates among patients living in communities with lower socioeconomic characteristics, such as a metropolitan statistical area (MSA vs non-MSA; OR = 1.05, 95% CI = 1.04-1.07). A higher risk adjustment summary score, indicating worse health status, was associated with an increased likelihood of medication nonadherence (OR = 1.21; 95% CI = 1.20-1.22). These patterns were similar among the full and partial LIS groups. CONCLUSIONS: Individual- and community-level characteristics were associated with the likelihood of medication nonadherence among Medicare LIS recipients with type 2 diabetes, hypertension, or heart failure. These characteristics included younger age, male sex, racial/ethnic minorities, living in lower socioeconomic communities, and a higher risk adjustment summary score. This study provided insight into medication nonadherence within the Medicare LIS population and identified the need to consider these factors when developing future policies to improve medication adherence. DISCLOSURES: This study was funded by the Pharmaceutical Research & Manufacturers of America (PhRMA), which was involved in the preparation and revision of the manuscript. Dougherty is employed by PhRMA. Todor was a PQA-CVS Health Foundation Scholar who was funded to work on this study. Hines is employed by Pharmacy Quality Alliance. Wang reports grants from AbbVie, Curo, Bristol Myers Squibb, and Pfizer, during the time of this study, and fees from the PhRMA Foundation for work on its Heath Outcomes Research Advisor Committee. The other authors have nothing to disclose. This study was presented as a poster at the online 2020 PQA Annual Meeting, May 7, 2020.

Racial/ethnic disparities in measure calculations for Part D Star Ratings among Medicare beneficiaries with diabetes, hypertension, and/or hyperlipidemia.

BACKGROUND: Previous literature reported racial/ethnic disparities in the measure assessment of diabetes medication adherence in the Medicare Part D Star Ratings program. OBJECTIVE: This study examined the likelihood of inclusion in measure calculation across racial/ethnic groups for adherence metrics in Part D Star Ratings among individuals with diabetes, hypertension, and/or hyperlipidemia. METHODS: This was a retrospective cross sectional analysis of a 10% random sample of 2017 Medicare claims linked to Area Health Resources Files. Inclusion in measure calculation was determined based on inclusion/exclusion criteria in adherence metrics for adherence medications for diabetes, hypertension, and hyperlipidemia in Part D Star Ratings developed by the Pharmacy Quality Alliance. Logistic regression and multinomial logistic regression were used to adjust for patient/community characteristics. RESULTS: The study sample size was 2 707 216. Compared to Non-Hispanic White (White) beneficiaries, minorities were more likely to be excluded from measure calculation among individuals with 1 condition. For example, among individuals with hypertension, compared to White individuals, the adjusted odds ratios for exclusion for Black, Hispanic, Asian/Pacific Islander and other individuals were 1.46 (95% confidence interval, or CI = 1.42-1.50), 1.38 (95% CI = 1.33-1.43), 1.28 (95% CI = 1.21-1.35), and 1.08 (95% CI = 1.02-1.15), respectively. Among individuals with more than 1 chronic condition, minorities were more likely to be included in fewer calculations for medication adherence measures. For example, among individuals with all 3 conditions, the adjusted relative risk ratios for Black, compared to White, beneficiaries for being included in 0, 1, and 2 measures, versus all 3 measures, were 2.14 (95% CI = 1.99-2.30), 1.49 (95% CI = 1.41-1.56), 1.20 (95% CI = 1.18-1.23), respectively. CONCLUSIONS: Compared to White beneficiaries, racial/ethnic minorities are more likely to be excluded from the calculation for adherence measures among individuals with diabetes, hypertension, and/or hyperlipidemia. Future studies should examine whether such disparities exacerbate existing racial/ethnic disparities in health outcomes and devise solutions for these disparities.

Association Between Medication Adherence and Healthcare Costs Among Patients Receiving the Low-Income Subsidy.

OBJECTIVES: Significant literature exists on the effects of medication adherence on reducing healthcare costs, but less is known about the effect of medication adherence among Medicare low-income subsidy (LIS) recipients. This study examined the effects of medication adherence on healthcare costs among LIS recipients with diabetes, hypertension, and/or heart failure. METHODS: This retrospective study analyzed Medicare claims data (2012-2013) linked to the Area Health Resources Files. Using measures developed by the Pharmacy Quality Alliance, adherence to 11 medication classes was studied among patients with 7 possible combinations of the diseases mentioned. Adherence was measured in 8 categories of proportion of days covered (PDC): ≥95%, 90% to <95%, 85% to <90%, 80% to <85%, 75% to <80%, 50% to <75%, 25% to <50%, and <25%. Annual Medicare costs were compared across adherence categories. A generalized linear model was used to control for patient/community characteristics. RESULTS: Among patients with only one disease, such as diabetes, patients with the lowest adherence (PDC < 25%) had $3152/year higher Medicare costs than patients with the highest adherence (PDC ≥ 95%; $11 101 vs $7949; P < .05). The adjusted costs among patients with PDC < 25% was $1893 higher than patients with PDC ≥ 95% ($9919 vs $8026; P < .05). Among patients with multiple chronic conditions, patients' adherence to medications for fewer diseases had higher costs. CONCLUSIONS: Greater medication adherence is associated with lower Medicare costs in the Medicare LIS population. Future policy affecting the LIS program should encourage better medication adherence among patients with chronic diseases.