Objective
To evaluate the effect of dual use of VA/Medicare Part D drug benefits on antihypertensive medication supply in older Veterans with dementia.
Data Sources/Study Setting
National, linked 2007–2010 Veterans Affairs (VA) and Medicare utilization and prescription records for 50,763 dementia patients with hypertension.
Study Design
We used inverse probability of treatment (IPT)‐weighted multinomial logistic regression to examine the association of dual prescription use with undersupply and oversupply of antihypertensives.
Data Collection/Extraction Methods
Veterans Affairs and Part D prescription records were used to classify patients as VA‐only, Part D‐only, or dual VA/Part D users of antihypertensives and summarize their antihypertensive medication supply in 2010: (1) appropriate supply of all prescribed antihypertensive classes, (2) undersupply of ≥1 class with no oversupply of another class, (3) oversupply of ≥1 class with no undersupply, or (4) both undersupply and oversupply.
Principal Findings
Dual prescription users were more likely than VA‐only users to have undersupply only (aOR = 1.28; 95 percent CI = 1.18–1.39), oversupply only (aOR = 2.38; 95 percent CI = 2.15–2.64), and concurrent under‐ and oversupply (aOR = 2.89; 95 percent CI = 2.53–3.29), versus appropriate supply of all classes.
Conclusions
Obtaining antihypertensives through both VA and Part D was associated with increased antihypertensive under‐ and oversupply. Efforts to understand how best to coordinate dual‐system prescription use are critically needed.