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.