Patterns of medication adherence and health care utilization among patients with chronic disease who were enrolled in a pharmacy assistance program

Poor medication adherence due to high drug costs is a barrier to optimal health outcomes among low-income uninsured patients with chronic conditions. Charitable pharmacy assistance programs provide medications to such patients, but little is known about the utilization patterns of program participants.

We used a retrospective cohort design to investigate 6-month outcomes for participants in the University of North Carolina (UNC) Health Care Pharmacy Assistance Program (PAP) who received medications indicated for hypertension, diabetes, and/or hyperlipidemia from 2009 through 2011. Logistic regression was used to analyze predictors of medication adherence and to evaluate the association between adherence and use of emergency and inpatient care.

The 3 study cohorts included 866 patients receiving antihypertensive agents, 265 patients receiving oral glucose-lowering agents, and 455 patients receiving statins. When assessed 6 months after program enrollment, 52%, 45%, and 38% of patients in these 3 groups, respectively, were at least 80% adherent to treatment. Adherent patients in all cohorts had lower odds of requiring inpatient or emergency department care, but the decrease was only statistically significant among those taking antihypertensive agents (odds ratio for hospitalization = 0.58; 95% confidence interval, 0.39-0.87).

Selection bias and inability to capture utilization data from sources other than UNC Health Care may have biased results.

Approximately 50% of PAP participants were adherent to chronic disease medications. Adherence to such therapies among patients who are receiving financial assistance with medications may reduce their need for costly health care services. Future research should assess the long-term ability of pharmacy assistance programs to promote medication adherence and should examine alternative strategies for improving adherence and health outcomes among low-income uninsured patients.