Association of Antihypertensive Medication Adherence With Healthcare Use and Medicaid Expenditures for Acute Cardiovascular Events.

Abstract

We assessed the impact of antihypertensive medication (AHM) adherence on the incidence and associated Medicaid costs of acute cardiovascular disease (CVD) events among Medicaid beneficiaries. The study cohort (n=59,037) consists of nonelderly adults continuously enrolled (36 mo and above) in a Medicaid fee-for-service program. AHM adherence was calculated using the medication possession ratio (MPR) and stratified to low (MPR<60%), moderate (60%≤MPR<80%), and high (MPR≥80%) levels. We used a proportional hazard model to estimate risk for acute CVD events and generalized linear models to estimate Medicaid per-patient-per-year costs. Low and moderate adherence subgroups had about 1.8 and 1.4 times higher risk of acute CVD events, compared with high adherence subgroup. By adherence level, Medicaid per-patient per-year costs for (1) CVD-related emergency department visits and hospitalizations were $661 (low), $479 (moderate), and $343 (high) and (2) AHMs were $430 (low), $604 (moderate), and $664 (high). Costs for CVD events and AHMs combined were similar across adherence subgroups. Lower adherence to AHM was associated with progressively higher CVD risk. The increase in medication cost from higher AHM adherence was offset solely by reduced Medicaid spending on acute CVD events.