A Systems-Level Approach to Improving Medication Adherence in Hypertensive Latinos: a Randomized Control Trial

Abstract

BACKGROUND: Despite numerous interventions targeting medication adherence in patients with uncontrolled hypertension, practice-based trials in Latino patients are scant. OBJECTIVE: To evaluate the effect of a systems-level adherence intervention, delivered by medical assistants (MAs), versus a comparison condition on medication adherence and blood pressure (BP) in 119 hypertensive Latino patients who were initially non-adherent to their antihypertensive medications. STUDY DESIGN: Randomized control trial. PARTICIPANTS: Patients (50% women; mean age, 61 years) were recruited from April 2013 to August 2015 in a community-based practice in New York. INTERVENTION: Systems-level approach that included an office system component built into the electronic health record and a provider support component consisting of nine MA-delivered health coaching sessions for improving medication adherence. The comparison group received the standard health coaching procedures followed at the clinic. MAIN OUTCOME MEASURES: The primary outcome was rate of medication adherence measured by an electronic monitoring device (EMD) across 6 months. The secondary outcomes were self-reported medication adherence measured by the eight-item Morisky Medication Adherence Scale (MMAS-8) and BP reduction from baseline to 6 months. KEY RESULTS: Adherence as measure by EMD worsened for both groups (p = 0.04) with no between-group difference (- 9.6% intervention and - 6.6% control, p = 0.66). While systolic BP improved in both groups, the difference between groups was not significant (- 6 mmHg in intervention vs. - 2.7 mmHg in control, p = 0.34). In contrast, the intervention group had a greater improvement in self-reported adherence (mean change 1.98 vs. 1.26, p = 0.03) when measured using the MMAS-8. CONCLUSIONS: Among Latinos with poorly controlled BP who were non-adherent to their antihypertensive medications, a systems-level intervention did not improve adherence as measured by EMD nor blood pressure. However, many patients reported challenges to using the EMD. Improvements in self-reported adherence suggest that this measure captures different aspects of adherence behavior than EMD. CLINICAL TRIAL REGISTRATION: NCT03560596.