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

Abstract

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