We examined associations between enrollment in Medicare Part D pharmacy benefits and changes in medication acquisition from Department of Veterans Affairs (VA) pharmacies. We included all women and a random 10% sample of men who were VA enrollees, ≥65 years old as of January 1, 2004, and alive through December 2007. We used difference-in-differences models with propensity score weighting to examine changes in medication acquisition between 2005 (before Part D was implemented) and 2007 (after Part D implementation) for veterans who were or were not Part D enrolled. Of 231,716 veterans meeting inclusion criteria, 49,881 (21.5%) were enrolled. While 30-day medication supplies decreased from 26.2 to 23.4 for enrolled veterans, they increased from 36.6 to 37.4 for nonenrolled veterans (difference-in-differences: −4.0, p < .001). Reductions in 30-day supplies were greater among veterans who were required to pay VA copayments for some or all medications and who used VA and Medicare outpatient services.
Effect of Dual Use of Veterans Affairs and Medicare Part D Drug Benefits on Antihypertensive Medication Supply in a National Cohort of Veterans with Dementia
