The Impact of Medicare Part D Antidementia Medication Therapy Management on Adherence

Image Credit: Adobe Stock Images/MonkeyBusiness.com

The umbrella term Alzheimer's disease and related dementias (ADRD) is intended to include Alzheimer's disease (AD) along with other forms of dementia, vascular contributions to cognitive impairment and dementia frontotemporal degeneration, mixed etiology dementias, and Lewy body dementia.

In 2021, it was estimated that more than six million Americans aged 65 years and older have ADRD, comprising 11% of the nation’s population for the particular age group. By 2060, This approximation is expected to more than double to nearly 14 million.

As of now, no treatment for the cure or slowing of ADRD’s progression exists, and for the six FDA-approved drugs that were approved in the space (donepezil, galantamine, rivastigmine, memantine, and memantine combined with donepezil), these are antidementia-based medications and work to diminish any cognitive symptoms.

Given these challenges, an observational study published in Exploratory Research in Clinical and Social Pharmacy¹ sought to further analyze the Centers for Medicare and Medicaid Services (CMS)’ Medicare medication therapy management (MTM) program's impact on racial/ethnic disparities, when it comes to adherence to antidementia medications among patients with Alzheimer's disease and other related dementias. Medicare Part D sponsors are required to provide MT services to eligible Medicare beneficiaries for this outpatient prescription drug benefit.

With the help of 2010–2017 Medicare Parts A/B/D administrative data that was connected to the Master Beneficiary Summary File and Area Health Resources Files (AHRF), the investigators conducted a retrospective study. The data contained information surrounding beneficiary demographic characteristics, diagnosis records, medication fills, and MTM enrollment, while the AHRF offered county-level data regarding the socioeconomic and health service characteristics of the beneficiaries' county of residence. All of the Medicare data were accessed through the CMS Virtual Research Data Center (VRDC).

The study sample was designed using the following four beneficiary characteristics:

1. Were given an ADRD diagnosis
2. Were at least 65 years of age at the beginning of 2016 and alive at the end of 2017
3. Retained continuous Parts A, B, and D coverage
4. Had at least two prescription claims for antidementia medications, along with more than 60 days of supply in each of the two years

In order to create intervention and comparison groups with comparable characteristics, propensity score matching was conducted. Investigators used a difference-in-differences model with logistic regression, including interaction terms of dummy variables for the intervention group and racial/ethnic minorities.

Results indicated that Asian/Pacific Islander, Black, and Hispanic patients were more likely to be non-adherent than non-Hispanic White (White) patients in 2016. Also, the differences in odds of nonadherence between Black and White patients among the intervention group were lower in 2017 than in 2016 by 27% (odds ratios [OR]: 0.73, 95% confidence interval [CI]: 0.65–0.82).

A similar decrease was seen between Hispanic and White patients by 26% (OR: 0.74, 95% CI: 0.63–0.87). MTM enrollment was associated with reduced disparities in non-adherence for Black-White patients of 33% (OR: 0.67, 95% CI: 0.57–0.78) and Hispanic-White patients of 19% (OR: 0.81, 95% CI: 0.67–0.99).

As a result, the study authors concluded that, “The Medicare MTM program was associated with reduced racial/ethnic disparities in adherence to anti-dementia medications between older Blacks and Whites, as well as between older Hispanics and Whites. No effect of the program was detected on the disparities between Asians and Whites. Our results suggested that a lower level of health care access and a heavier disease burden may lead to higher nonadherence, whereas a higher level of social support may reduce nonadherence. Incorporating caregiver and provider education in the MTM program may facilitate more effective and sustainable service delivery. Future research is warranted to investigate the specific areas of training related to Medicare MTM services that caregivers and frontline providers may need so that the MTM program's benefits may be optimized.”

Reference

1. Dong X, Tsang CCS, Wan JY, Chisholm-Burns MA, Finch CK, Tsao JW, Browning JA, Garuccio J, Zeng R, Wang J. Effects of Medicare Part D medication therapy management on racial/ethnic disparities in adherence to antidementia medications among patients with Alzheimer's disease and related dementias: An observational study. Explor Res Clin Soc Pharm. 2024 Feb 10;13:100420. doi: 10.1016/j.rcsop.2024.100420. PMID: 38420610; PMCID: PMC10900920.