Association of Race and Ethnicity and Anticoagulation in Patients with Atrial Fibrillation Dually Enrolled in VA and Medicare: Effects of Medicare Part D on Prescribing Disparities

Background: Racial and ethnic disparities in anticoagulation exist in atrial fibrillation (AF) management in Medicare and the Veterans Health Administration (VA), but the influence of dual VA and Medicare enrollment is unclear. We compared anticoagulant initiation by race and ethnicity in dually enrolled patients and assessed the role of Medicare Part D enrollment on anticoagulation disparities. Methods: We identified patients with incident AF (2014-2018) dually enrolled in VA and Medicare. We assessed any anticoagulant initiation (warfarin or direct-acting oral anticoagulants, DOACs) within 90 days of AF diagnosis and DOAC use among anticoagulant initiators. We modeled anticoagulant initiation, adjusting for patient, provider, and facility factors, including main effects for race and ethnicity and Medicare Part D enrollment and an interaction term for these variables. Results: In 43,789 patients, 8.9% were Black, 3.6% Hispanic, and 87.5% White; 10.9% participated in Medicare Part D. Overall, 29,680 (67.8%) patients initiated any anticoagulant, of which 17,568 (59.2%) initiated DOACs. Lower proportions of Black (65.2%) than Hispanic (67.6%) or White (68.0%) patients initiated any anticoagulant (p= 0.001), and lower proportions of Black (56.3%) and Hispanic (55.9%) than White (59.6%) patients (p=0.001) initiated DOACs. Compared to White patients, Black patients had significantly lower initiation of any anticoagulant, adjusted odds ratio (aOR) 0.89; 95% CI 0.82-0.97. The aORs for DOAC initiation were significantly lower for Black (0.72; 95% CI, 0.65-0.81) and Hispanic (0.84; 95% CI, 0.70-1.00) than White patients.The interaction between race and ethnicity and Medicare Part D enrollment was non-significant for any anticoagulant (p=0.99) and DOAC (p=0.27) therapies. Conclusions: In dually enrolled VA and Medicare patients with AF, Black patients were less likely to initiate any anticoagulant and Black and Hispanic patients were less likely to initiate DOACs. Medicare Part D enrollment did not moderate the associations between race and ethnicity and anticoagulant therapies.

Characteristics of dual drug benefit use among veterans with dementia enrolled in the Veterans Health Administration and Medicare Part D

BACKGROUND

Obtaining prescription medications from multiple health systems may complicate coordination of care. Older Veterans who obtain medications concurrently through Veterans Affairs (VA) benefits and Medicare Part D benefits (dual users) are at higher risk of unintended negative outcomes.

OBJECTIVE

To explore characteristics predicting dual drug benefit use from both VA and Medicare Part D in a national sample of older Veterans with dementia.

METHODS

Administrative data were obtained from the VA and Medicare for a national sample of 110,828 Veterans with dementia ages 68 and older in 2010. Veterans were classified into three drug benefit user groups based on the source of all prescription medications they obtained in 2010: VA-only, Part D-only, and Dual Use. Multinomial logistic regression was used to examine predictors of drug benefit user group. The source of prescriptions was described for each of the ten most frequently used drug classes and opioids.

RESULTS

Fifty-six percent of Veterans received all of their prescription medications from VA-only, 28% from Part D-only, and 16% from both VA and Part D. Veterans who were eligible for Medicaid or who had a priority group score conferring less generous drug benefits within the VA were more likely to be Part D-only or dual users. Nearly one fourth of Veterans taking opioids concurrently received opioid prescriptions from dual sources (24.7%).

CONCLUSIONS

Medicaid eligibility and Veteran priority group status, which largely decrease copayments for drugs obtained outside versus within the VA, respectively, were the main factors predicting drug user benefit group. Policies to encourage single-system prescribing and enhance communication across health systems are crucial to preventing negative health outcomes related to care fragmentation.

Impact of Dual Use of Department of Veterans Affairs and Medicare Part D Drug Benefits on Potentially Unsafe Opioid Use

OBJECTIVES

To estimate the prevalence and consequences of receiving prescription opioids from both the Department of Veterans Affairs (VA) and Medicare Part D.

METHODS

Among US veterans enrolled in both VA and Part D filling 1 or more opioid prescriptions in 2012 (n = 539 473), we calculated 3 opioid safety measures using morphine milligram equivalents (MME): (1) proportion receiving greater than 100 MME for 1 or more days, (2) mean days receiving greater than 100 MME, and (3) proportion receiving greater than 120 MME for 90 consecutive days. We compared these measures by opioid source.

RESULTS

Overall, 135 643 (25.1%) veterans received opioids from VA only, 332 630 (61.7%) from Part D only, and 71 200 (13.2%) from both. The dual-use group was more likely than the VA-only group to receive greater than 100 MME for 1 or more days (34.3% vs 10.9%; adjusted risk ratio [ARR] = 3.0; 95% confidence interval [CI] = 2.9, 3.1), have more days with greater than 100 MME (42.5 vs 16.9 days; adjusted difference = 16.4 days; 95% CI = 15.7, 17.2), and to receive greater than 120 MME for 90 consecutive days (7.8% vs 3.1%; ARR = 2.2; 95% CI = 2.1, 2.3).

CONCLUSIONS

Among veterans dually enrolled in VA and Medicare Part D, dual use of opioids was associated with more than 2 to 3 times the risk of high-dose opioid exposure.