Association of Medicare Part D low-income cost subsidy program enrollment with increased fill adherence to clopidogrel after coronary stent placement

Income and antiplatelet adherence following percutaneous coronary intervention

Objective

To investigate the relation of annual household income to antiplatelet adherence following PCI.

Background

Treatment with 6–12 months of dual antiplatelet therapy (DAPT) following percutaneous coronary intervention (PCI) is a Class I recommendation. Adherence to these medications is essential to reduce risk of stent thrombosis and recurrent ischemic events. Social risk factors like household income modify how patients access and adhere to essential pharmacologic therapies such as antiplatelet agents.

Methods

We identified individuals presenting with PCI in an administrative claims database of commercially insured and Medicare Advantage beneficiaries from 2017 to 2019. We collected data on age, sex, race, ethnicity, educational attainment, and covariates (prevalent coronary disease, medications, healthcare visits, insurance type, copay, antiplatelet medications, and Elixhauser Comorbidity Index conditions). We related annual household income, categorized as <$40,000; $40–49,999; $50–59,999; $60–74,999; $75–99,999; and ≥$100 K, to proportion of days covered (PDC) in multivariable-adjusted regression models. We defined non-adherence as PDC <80%.

Results

Our dataset included 90,163 individuals (age 69.0 ± 10.9 years, 33.1% women, 25.1% non-White race) who underwent PCI. We observed graded, decreased antiplatelet adherence across income categories: rates of PDC≥80% decreased with successively lower income. Individuals with annual income <$40,000 had 1.5-fold higher odds of non-adherence (95% CI, 1.40–1.56) compared to those with income ≥$100,000 after multivariable adjustment.

Conclusions

In a claims-based analysis, we determined that lower income is associated with decreased likelihood of adherence to antiplatelet agents following PCI. Our results indicate the importance of considering social risk factors in the evaluation of barriers to antiplatelet adherence following PCI.

Towards better reporting of the Proportion of Days Covered method in cardiovascular medication adherence: A scoping review and new tool TEN-SPIDERS

Although medication adherence is commonly measured in electronic datasets using the proportion of days covered (PDC), no standardized approach is used to calculate and report this measure. We conducted a scoping review to understand the approaches taken to calculate and report the PDC for cardiovascular medicines to develop improved guidance for researchers using this measure. After prespecifying methods in a registered protocol, we searched Ovid Medline, Embase, Scopus, CINAHL Plus and grey literature (1 July 2012 to 14 December 2020) for articles containing the terms “proportion of days covered” and “cardiovascular medicine”, or synonyms and subject headings. Of the 523 articles identified, 316 were reviewed in full and 76 were included (93% observational studies; 47% from the USA; 2 grey literature articles). In 45 articles (59%), the PDC was measured from the first dispensing/claim date. Good adherence was defined as 80% PDC in 61 articles, 56% of which contained a rationale for selecting this threshold. The following parameters, important for deriving the PDC, were often not reported/unclear: switching (53%), early refills (45%), in‐hospital supplies (45%), presupply (28%) and survival (7%). Of the 46 articles where dosing information was unavailable, 59% reported how doses were imputed. To improve the transparent and systematic reporting of the PDC, we propose the TEN‐SPIDERS tool, covering the following PDC parameters: Threshold, Eligibility criteria, Numerator and denominator, Survival, Presupply, In‐hospital supplies, Dosing, Early Refills, and Switching. Use of this tool will standardize reporting of the PDC to facilitate reliable comparisons of medication adherence estimates between studies.

Accurate Medication Adherence Measurement Using Administrative Data for Frequently Hospitalized Patients

Background: Pharmacy administrative claims data remain an accessible and efficient source to measure medication adherence for frequently hospitalized patient populations that are systematically excluded from the landmark drug trials. Published pharmacotherapy studies use medication possession ratio (MPR) and proportion of days covered (PDC) to calculate medication adherence and usually fail to incorporate hospitalization and prescription overlap/gap from claims data. To make the cacophony of adherence measures clearer, this study created a refined hospital-adjusted algorithm to capture pharmacotherapy adherence among patients with end-stage renal disease (ESRD). Methods: The United States Renal Data System (USRDS) registry of ESRD was used to determine prescription-filling patterns of those receiving new prescriptions for oral P2Y12 inhibitors (P2Y12-I) between 2011 and 2015. P2Y12-I-naïve patients were followed until death, kidney transplantation, discontinuing medications, or loss to follow-up. After flagging/censoring key variables, the algorithm adjusted for hospital length of stay (LOS) and medication overlap. Hospital-adjusted medication adherence (HA-PDC) was calculated and compared with traditional MPR and PDC methods. Analyses were performed with SAS software. Results: Hospitalization occurred for 78% of the cohort (N = 46 514). The median LOS was 12 (interquartile range [IQR] = 2-34) days. MPR and PDC were 61% (IQR = 29%-94%) and 59% (IQR = 31%-93%), respectively. After applying adjustments for overlapping coverage days and hospital stays independently, HA-PDC adherence values changed in 41% and 52.7% of the cohort, respectively. When adjustments for overlap and hospital stay were made concurrently, HA-PDC adherence values changed in 68% of the cohort by 5.8% (HA-PDC median = 0.68, IQR = 0.31-0.93). HA-PDC declined over time (3M-6M-9M-12M). Nearly 48% of the cohort had a ≥30 days refill gap in the first 3 months, and this increased over time (P < .0001). Conclusions: Refill gaps should be investigated carefully to capture accurate pharmacotherapy adherence. HA-PDC measures increased adherence substantially when adjustments for hospital stay and medication refill overlaps are made. Furthermore, if hospitalizations were ignored for medications that are included in Medicare quality measures, such as Medicare STAR program, the apparent reduction in adherence might be associated with lower quality and health plan reimbursement.

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.

[Clinical and economic consequences in patients initiating therapy with clopidogrel brand-name vs. generic: A real-life retrospective study]

OBJECTIVE

To evaluate the adherence to treatment, resource use, and costs in subjects initiating treatment with brand-name versus generic clopidogrel for acute coronary syndrome (ACS) and peripheral arterial disease (PAD).

PATIENTS AND METHODS

Observational, retrospective study based on the medical records of patients aged ≥18 years who initiated treatment with clopidogrel (brand-name vs. generic) between 4 April 2015 and 31 March 2017. Four study groups were compared, and the follow-up was one year. The main measurements were: comorbidity, treatment adherence, medication possession ratio (MPR), resource use, and costs. The results were analysed using multivariate analysis. The level of statistical significance was P<.05.

RESULTS

Four groups were compared: a) ACS: brand-name clopidogrel (N=1,067) vs. generic (N=3,504), and b) PAD: brand-name clopidogrel (N=425) vs. generic (N=994). In the ACS comparison (mean age: 69.7 years, 61.4% male), adherence (65.3% vs. 61.0%, P<.001), adjusted hazard ratio 0.85 and MPR (89.8% vs. 86.7%, P=.045) were more superior with brand-name clopidogrel than with the generic and with a lower mean cost per unit (€2,890 vs. €3,865, P=.001). In the PAD comparison, similar results were observed: persistence (64.7% vs. 58.9%, P=.039); adjusted hazard-ratio 0.86 and MPR (88.6% vs. 81.7%; P=.013) were more superior with brand-name clopidogrel than for the generic, with a lower mean cost per unit (€2,880 vs. €3,532, P=.044).

CONCLUSIONS

There was better treatment adherence in patients initiating treatment with brand-name compared with generic clopidogrel for ACS and PAD, resulting in lower health costs for the Spanish National Health System.

Decomposing the effect of drug benefit program on antihypertensive medication adherence among the elderly in urban China

PURPOSE

Hypertension is a rapidly growing epidemic in People's Republic of China, yet it remains inadequately controlled. This study aimed to identify the relative contributions of program effects and patients' characteristics to the differences in antihypertensive medication nonadherence between drug benefit program enrollees and non-enrollees.

PATIENTS AND METHODS

Data were from a cross-sectional survey of 1,969 community-dwelling elderly adults with hypertension. Self-reported adherence was measured following previous studies in People's Republic of China. The Blinder-Oaxaca nonlinear decomposition method was used to identify the relative contributions of program effects and patients' individual characteristics.

RESULTS

Eleven percent of the drug benefit program enrollees were nonadherent to their medication, while 17% of non-enrollees were. Blinder-Oaxaca decomposition identified that over 60% of the gap between the two groups was due to the program effects (P=0.024). The rest could be explained by differences in observable characteristics (P<0.001), such as diabetic status, duration of hypertension, and blood pressure control.

CONCLUSION

The study confirmed that drug benefit program enrollees were more likely to be adherent to their antihypertensive medication than non-enrollees in the context of People's Republic of China.

Association between Higher Generic Drug Use and Medicare Part D Star Ratings: An Observational Analysis

BACKGROUND

Increasing generic drug use, due to potential for cost savings and drug access, is a viable consideration for Medicare prescription drug plans to achieve high star ratings and improve quality of plan offerings for Medicare beneficiaries.

OBJECTIVE

To examine the association between contract-level proportion of generic drugs dispensed (pGDD) and Medicare Part D star ratings.

METHODS

This was a retrospective study of linked 2011 Medicare Part D star rating data with contract-level pGDD data. A total of 477 individual Medicare prescription contracts were included, representing 75% of total Prescription Drug Plans and more than 65% of total Medicare Advantage Prescription Drug Plans available by the end of 2010. Primary outcomes were Medicare Part D summary and domain star ratings (1-5 indicating lowest to highest performance), incorporating a range of quality measures for access, cost, beneficiary satisfaction, and health services outcomes and processes. Ordinal logistic regression models were used to examine associations between pGDD and Medicare Part D summary and domain star ratings, controlling for contract type and number of beneficiary enrollment.

RESULTS

Higher pGDD was associated with higher summary star ratings (adjusted odds ratio 1.08 with 95% confidence interval 1.04-1.12) and higher "member experience with drug plan" domain ratings (adjusted odds ratio 1.07 with 95% confidence interval 1.03-1.11).

CONCLUSIONS

Prescription formulary benefit design targeting increasing generic drug use appears to be associated with improved member experience and higher plan star ratings. Consideration may be given to incorporating pGDD into Medicare Part D star rating measures to improve quality of prescription plans.

Adherence to tyrosine kinase inhibitors among Medicare Part D beneficiaries with chronic myeloid leukemia

BACKGROUND

Tyrosine kinase inhibitors (TKIs) improve the survival of patients with chronic myeloid leukemia (CML) dramatically; however, nonadherence to TKI therapy may lead to resistance to the therapy. TKIs are very expensive and are covered under Part D insurance for Medicare patients. To the authors' knowledge, the impact of low-income subsidy status and cost sharing on adherence among this group has not been well studied in the literature.

METHODS

Surveillance, Epidemiology, and End Results (SEER) registry data linked with Medicare Part D data from the years 2007 through 2012 were used in the current study. The authors identified 836 patients with CML with Medicare Part D insurance coverage who were new TKI users. Treatment nonadherence was defined as a binary variable indicating the percentage of days covered was <80% during the 180-day period after the initiation of TKI therapy. Logistic regression was used to examine the relationship between out-of-pocket costs per 30-day drug supply, Medicare Part D plan characteristics, and treatment adherence while controlling for other patient characteristics.

RESULTS

Overall, 244 of the 836 patients with CML (29%) were nonadherent to targeted oral therapy during the 180 days after the initiation of treatment with TKIs. The multivariable logistic regression demonstrated that patients with heavily subsidized (odds ratio, 6.7; 95% confidence interval, 2.8-15.9) and moderately subsidized (odds ratio, 3.0; 95% confidence interval, 1.4-6.5) Medicare Part D plans were much more likely to demonstrate nonadherence compared with patients without a subsidy.

CONCLUSIONS

The current population-based study found a significantly higher rate of nonadherence among heavily subsidized patients with substantially lower out-of-pocket costs, which suggests that future research is needed to help lower the nonadherence rate among these individuals. Cancer 2018;124:364-73. © 2017 American Cancer Society.

Medicare Part D's Effects on Drug Utilization and Out-of-Pocket Costs: A Systematic Review

OBJECTIVE

To update a past systematic review on whether Medicare Part D changed drug utilization and out-of-pocket (OOP) costs overall and within subpopulations, and to identify evidence gaps.

DATA SOURCES/STUDY SETTING

Published and gray literature from 2010 to 2015 meeting prespecified screening criteria, including having a comparison group, and utilization or OOP cost outcomes.

STUDY DESIGN

We conducted a systematic literature review with a quality assessment.

DATA COLLECTION/EXTRACTION METHODS

For each study, we extracted information on study design, data sources, analytic methods, outcomes, and limitations. Because outcome measures vary across studies, we did a qualitative synthesis rather than meta-analysis.

PRINCIPAL FINDINGS

Sixty-five studies met screening criteria. Overall, Medicare Part D enrollees have increased drug utilization and decreased OOP costs, but coverage gaps limit the program's impact. Beneficiaries whose insurance becomes more generous after enrollment had disproportionately increased drug utilization and decreased OOP costs. Outcomes among dual-eligibles were mixed.

CONCLUSIONS

There is strong evidence on how Medicare Part D and the donut hole coverage gap affect utilization and OOP costs, but weak evidence on how effects vary among dual-eligibles or across diseases. Findings suggest that the Affordable Care Act's provisions to expand coverage and reduce the donut hole should improve patient outcomes.