National Utilization Patterns of Warfarin Use in Older Patients with Atrial Fibrillation: A Population-Based Study of Medicare Part D Beneficiaries

BACKGROUND Although warfarin therapy reduces stroke incidence in patients with atrial fibrillation (AF), the rate of warfarin use in this population remains low. In 2008, the Medicare Part D program was expanded to pay for medications for Medicare enrollees. OBJECTIVE To examine rates and predictors of warfarin use in Medicare Part D beneficiaries with AF. METHODS This population-based retrospective cohort study used claims data from 41,447 Medicare beneficiaries aged 66 and older with at least 2 AF diagnoses in 2007 and at least 1 diagnosis in 2008. All subjects had continuous Medicare Part D prescription coverage in 2008. Statistical analysis using χ2 was used to examine differences in warfarin use by patient characteristics (age, ethnicity, sex, Medicaid eligibility, comorbidities, contraindications to warfarin, and whether they visited a cardiologist or a primary care physician [PCP]), CHADS2 score (congestive heart failure, hypertension, age, diabetes, and stroke or transient ischemic attack; higher scores indicate higher risks of stroke), and geographic regions. Using hierarchical generalized linear models restricted to subjects without warfarin contraindications (n = 34,947), we examined the effect of patient characteristics and geographic regions on warfarin use. RESULTS The overall warfarin use rate was 66.8%. The warfarin use rates varied between hospital referral regions, with highest rates in the Midwestern states and lowest rates in the South. The regional variation persisted even after adjustment for patient characteristics. Multivariable analysis showed that the odds of being on warfarin decreased significantly with age and increasing comorbidity, in blacks, and among those with low income. Seeing a cardiologist (OR 1.10; 95% CI 1.05–1.16), having a PCP (OR 1.23; 95% CI 1.17–1.29), and CHADS2 score of 2 or greater (OR 1.09; 95% CI 1.01–1.17) were associated with increased odds of warfarin use. CONCLUSIONS Warfarin use rates vary by patient characteristics and region, with higher rates among residents of the Midwest and among patients seen by cardiologists and PCPs. Preventing stroke-related disability in AF requires implementation of evidence-based initiatives to increase warfarin use.

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Financial hardship among Medicare beneficiaries prescribed oral targeted therapies for advanced prostate cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.6_suppl.68 ◽

2020 ◽

Vol 38 (6_suppl) ◽

pp. 68-68

Author(s):

Megan Veresh Caram ◽

Mary Oerline ◽

Stacie Dusetzina ◽

Parth K. Modi ◽

Lindsey A. Herrel ◽

...

Keyword(s):

Prostate Cancer ◽

Low Income ◽

Advanced Prostate Cancer ◽

Medicare Part D ◽

Financial Hardship ◽

Medicare Part ◽

Regional Variability ◽

Part D ◽

Hospital Referral Region ◽

Hospital Referral

68 Background: Abiraterone and enzalutamide are increasingly being used to treat advanced prostate cancer. Understanding barriers to adhering to treatment is of paramount importance in ensuring continued access to these important therapies. Patients with limited resources or insufficient access to mechanisms that lower their out-of-pocket cost are likely to suffer from significant financial toxicity and may engage in coping mechanisms such as rationing or abandoning their medication. Methods: To address the variability in measures of financial hardship, we performed a retrospective cohort study on a 20% sample of patients eligible for Medicare Part D who received their first fill of abiraterone or enzalutamide between July 2013 and June 2015. Patients were assigned to a provider based on their first prescription, and a hospital referral region (HRR) based on their ZIP code. The primary outcomes were to determine the proportion of days covered (PDC), overall prescription adherence, and average monthly out-of-pocket cost to patients prescribed abiraterone or enzalutamide, all within the first six months of treatment. Results: From mid-2013 to mid-2015, 4529 patients filled abiraterone or enzalutamide through Medicare Part D, within 305 HRRs. There was substantial variability in PDC, adherence, and out-of-pocket cost to patients among HRRs. The mean PDC was 84% with mean adherence of 73%, which included the 393 (8.7%) of patients who abandoned oral therapy after 1-2 fills. The median standard monthly out-of-pocket cost was $707, ranging between $0 and $3505. Among patients with low-income subsidies, median out-of-pocket cost by HRR ranged from $0 to $2815. We observed that PDC tracked closely with socioeconomic status – HRRs that included a higher proportion of patients eligible for Medicaid had lower PDCs and adherence, but lower standard out-of-pocket cost. Conclusions: This investigation demonstrated significant variation in PDC, adherence, and out-of-pocket cost among different HRRs for patients prescribed abiraterone and enzalutamide and that much of the variability in financial hardship measures among HRRs may be due to socioeconomic variables and regional variability.

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Early National Dissemination of Abiraterone and Enzalutamide for Advanced Prostate Cancer in Medicare Part D

Journal of Oncology Practice ◽

10.1200/jop.2016.020206 ◽

2017 ◽

Vol 13 (8) ◽

pp. e694-e702 ◽

Cited By ~ 3

Author(s):

Megan E.V. Caram ◽

Tudor Borza ◽

Hye-Sung Min ◽

Jennifer J. Griggs ◽

David C. Miller ◽

...

Keyword(s):

Prostate Cancer ◽

United States ◽

Regional Variation ◽

Medicare Part D ◽

The United States ◽

Medicare Part ◽

Castration Resistant Prostate Cancer ◽

Part D ◽

Hospital Referral ◽

Early National

Introduction: Abiraterone and enzalutamide were approved by the Food and Drug Administration in 2011 and 2012 to treat men with metastatic castration-resistant prostate cancer (mCRPC). Most men with mCRPC are > 65 years of age and thus eligible for Medicare Part D. We conducted a study to better understand the early dissemination of these drugs across the United States using national Medicare Part D data. Methods: We evaluated the number of prescriptions for abiraterone and enzalutamide by provider specialty and hospital referral region (HRR) using Medicare Part D and Dartmouth Atlas data. We categorized HRRs by abiraterone and enzalutamide prescriptions, adjusted for prostate cancer incidence, and examined factors associated with regional variation using multilevel regression models. Results: Among providers who wrote the majority of prescriptions for abiraterone or enzalutamide in 2013 (n = 2,121), 87.5% were medical oncologists, 3.3% were urologists, and 9.2% were other provider specialties. Among prescribers, approximately 30% were responsible for three quarters of the claims for abiraterone and 20% were responsible for more than half the claims for enzalutamide. Some HRRs demonstrated low-prescribing rates despite average medical oncology and urology physician workforce density. Our multilevel model demonstrated that regional factors potentially influenced variation in care. Conclusion: The majority of prescriptions written for abiraterone and enzalutamide through Medicare Part D in 2013 were written by a minority of providers, with marked regional variation across the United States. Better understanding of the early national dissemination of these effective but expensive drugs can help inform strategies to optimize introduction of new, evidence-based mCRPC treatments.

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Using Matched Survey and Administrative Data to Estimate Eligibility for the Medicare Part D Low Income Subsidy Program

10.7249/wr743 ◽

2010 ◽

Cited By ~ 3

Author(s):

Erik Meijer ◽

Lynn Karoly ◽

Pierre-Carl Michaud

Keyword(s):

Administrative Data ◽

Low Income ◽

Medicare Part D ◽

Medicare Part ◽

Part D ◽

Subsidy Program

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The New Medicare Part D Prescription Drug Benefit: An Estimation of Its Effect on Prescription Drug Costs in a Medicare Population with Atrial Fibrillation

Yearbook of Cardiology ◽

10.1016/s0145-4145(08)06013-9 ◽

2008 ◽

Vol 2008 ◽

pp. 498-499

Author(s):

A.L. Waldo

Keyword(s):

Atrial Fibrillation ◽

Prescription Drug ◽

Medicare Part D ◽

Drug Costs ◽

Medicare Part ◽

Drug Benefit ◽

Part D ◽

Prescription Drug Benefit ◽

Medicare Population ◽

Prescription Drug Costs

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HOW DO FORMULARY RESTRICTIONS AFFECT MEDICATION USE AND COSTS FOR LOW-INCOME SUBSIDY RECIPIENTS IN MEDICARE PART D PLANS?

Value in Health ◽

10.1016/j.jval.2016.03.795 ◽

2016 ◽

Vol 19 (3) ◽

pp. A261

Author(s):

X. Shen ◽

B. Stuart ◽

C. Powers ◽

S. Tom ◽

L. Magder ◽

...

Keyword(s):

Low Income ◽

Medication Use ◽

Medicare Part D ◽

Medicare Part ◽

Part D

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Early national dissemination of abiraterone and enzalutamide for advanced prostate cancer in Medicare Part D.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.8_suppl.35 ◽

2017 ◽

Vol 35 (8_suppl) ◽

pp. 35-35

Author(s):

Megan Veresh Caram ◽

Tudor Borza ◽

Hye-Sung Min ◽

Jennifer J. Griggs ◽

David Christopher Miller ◽

...

Keyword(s):

Prostate Cancer ◽

United States ◽

Regional Variation ◽

Advanced Prostate Cancer ◽

Medicare Part D ◽

The United States ◽

Medicare Part ◽

Part D ◽

Hospital Referral ◽

Early National

35 Background: Abiraterone and enzalutamide are oral medications approved by the Food & Drug Administration in 2011 and 2012 to treat men with advanced castration-resistant prostate cancer. Most men with advanced prostate cancer are over age 65 and thus eligible for Medicare Part D. We conducted a study to better understand the early dissemination of these drugs across the United States using national Medicare Part D data. Methods: We evaluated the number of prescriptions for abiraterone and enzalutamide by provider specialty and hospital referral region (HRR) using Medicare Part D and Dartmouth Atlas data. We categorized HRRs by abiraterone and enzalutamide prescriptions, adjusted for prostate cancer incidence, and examined factors associated with regional variation using multilevel regression models. Results: Among all providers who wrote prescriptions for abiraterone or enzalutamide in 2013 (n=2121), 87.5% were medical oncologists, 3.3% urologists, and 9.2% were listed as other provider specialties. Among those who prescribed either drug, 5% of providers were responsible for 75% of the claims for abiraterone, and 7% were responsible for 75% of the claims for enzalutamide. Some HRRs demonstrated low-prescribing rates despite average medical oncology and urology physician workforce density. Conclusions: The majority of prescriptions written for abiraterone and enzalutamide through Medicare Part D in 2013 were written by a minority of providers with marked regional variation across the United States. Better understanding the early national dissemination of these effective but expensive drugs can help inform strategies to optimize introduction of new, evidence-based advanced prostate cancer treatments.

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