Effect of a Pharmacy-Based Health Literacy Intervention and Patient Characteristics on Medication Refill Adherence in an Urban Health System

BACKGROUND: Limited health literacy is associated with poor understanding of medication instructions and may be related to medication adherence. OBJECTIVE: To evaluate a 3-part intervention (automated telephone reminder calls to refill prescriptions, picture prescription card, and clear health communication training for pharmacists) intended to increase refill adherence through attention to health literacy. METHODS: Three pharmacies that serve a primarily indigent, minority population served as the intervention sites, and one pharmacy served as the control site. To evaluate the impact of the 6-month intervention on medication adherence, pharmacy refill data were used to calculate the cumulative medication gap (CMG), in which values close to zero indicate better adherence. The primary measure of treatment effect was a comparison of the change in refill adherence within each group, from baseline to follow-up. RESULTS: A total of 173 patients were enrolled in the intervention group and 102 patients in the control group. Medication adherence was significantly different between intervention (CMG = 0.25) and control (CMG = 0.18) groups at baseline (p = 0.004). Refill adherence in the intervention group improved slightly during follow-up (CMG = 0.23), while it worsened slightly in the control group (CMG = 0.21), but the change in adherence between intervention and control groups was not significantly different (p = 0.4). Between 80% and 90% of intervention participants indicated that receiving the picture prescription and phone call interventions helped them remember when and how to take their medications and refill their prescriptions. No patient characteristics, including health literacy, were consistently associated with adherence. CONCLUSIONS: Implementation of a 3-part intervention-automated telephone reminders, picture prescription card, and pharmacist communication skills training-did not significantly improve refill adherence among inner-city patients. Further study should explore whether other aspects of medication management, such as dosing or adverse events, can be improved through these types of interventions, implemented either alone or in combination.