OBJECTIVES

To examine the effects of adherence to a patient’s initial antihypertensive therapy on health resource utilization and health outcomes. Adherence was measured using the medication possession ratio (MPR).

METHODS

A retrospective analysis was conducted using data from a large private health insurance claims database, years 2007-2014. Subjects were included based on having at least 2 hypertension diagnosis and having filled an antihypertensive prescription (N=595,056). The date of the first fill is the subject’s index date, and subjects were required to have at least 6 months of data in the pre-index and 12 months post-index. MPR was calculated for the duration of therapy. Health related expenditures were calculated for both the pre and post periods, in terms of pharmacy, inpatient, medical, and total costs. Covariates of interest included age, gender, health insurance type, geographic region, comorbidities, and previous 6 months total health expenditures. Analyses on costs utilized generalized linear models (GLM) and 2-part regression models. Analyses for time to event outcomes will utilize Cox survival models.

RESULTS

Descriptively, 53% of the population is male, 80% of the population is under 65, 58% had a point-of-service health plan, 38% had an MPR of 1, and 14% an MPR less than 0.05.

Preliminary analyses indicate that a higher MPR correlates with higher pharmacy costs ($808, P<0.001), but lower medical (-$604, P<0.001), inpatient (-$745, P<0.001), and total health care costs (-$389, P<0.001). Time to event models are currently being finalized.

CONCLUSIONS

Adherence with antihypertensive drug therapy, as measured by MPR, is associated with lower medical, inpatient, and total health care costs.