OBJECTIVES

: Limited evidence exists investigating the association between Pharmacy Quality Alliance (PQA) measures for cholesterol and disease state control, healthcare utilization and costs. This study aimed to determine the relationship between PQA-defined adherence (≥80% proportion of days covered) and disease state control, healthcare utilization and costs for Medicare Supplemental beneficiaries using statin medications.

METHODS

: This one-year retrospective study utilized a cohort of eligible individuals (e.g., continuous enrollment) from Truven Health MarketScan® Medicare Supplemental Research Databases (2009-2015).The date of the first statin medication was the index date. Healthcare utilization and costs (adjusted to 2015 US dollars)during one-year post-index datewere compared between adherent and non-adherent patients using generalized linear models with log link and negative binomial (utilization) or gamma (costs) distribution (costs) adjusting for covariates (e.g., age, gender, Charlson Comorbidity Index).Beta coefficients were used to compute cost ratios (CR) and rate ratios (RR). A logistic regression model assessed the relationship between adherence and disease state control (controlled=low-density lipoprotein (LDL) level ≤100mg/dL). An alpha level of 0.001 was set a priori.

RESULTS

: A total of 77,174 individuals were included in the cohort; of those, 58,668 (76.0%) were adherent. More individuals in the adherent group had controlled LDL levels versus the non-adherent group (78.6%, 61.1%; p<0.001). Multivariable analyses showed adherent patients had: fewer inpatient (RR=0.725, 95% confidence interval [CI]=0.687, 0.766) and outpatient visits (RR=0.953, 95% CI=0.940, 0.965); lower inpatient (CR=0.717, 95% CI=0.705, 0.729) and total (CR=0.853, 95% CI=0.838, 0.868) costs; and increased odds of having controlled LDL levels (odds ratio=2.192, 95% CI=2.109, 2.278). Adherence was associated with lower average per member per month inpatient costs ($127.57) and total healthcare costs ($157.32) compared to nonadherence.

CONCLUSIONS

: Statin adherence was associated with fewer inpatient and outpatient visits, lower inpatient and total costs, and over twice the odds of having a controlled disease statecompared to nonadherence.