Pilot Study to Test the Effectiveness of Different Financial Incentives to Improve Medication Adherence

Abstract

Background: Medication nonadherence affects health care costs, morbidity, and mortality. Concepts from behavioral economics can guide the development of interventions to improve medication adherence.

Objective: To measure the relative effectiveness of 2 behavioral economic-based incentive structures to improve medication adherence.

Methods: This randomized controlled trial compared adherence among participants taking antihypertensive or antihyperlipidemic medications randomized to usual care (UC), guaranteed pay-out (GPO) incentives, or lottery incentives. Daily adherence was measured over a 90-day period using electronic caps (Medication Event Monitoring System [MEMS]). The GPO group received $30 up-front in a virtual account, with $0.50 deducted for each missed dose. Lottery group participants were eligible for a weekly $50 drawing, but only if they had taken their medication as prescribed all week. An electronic survey assessed self-reported adherence. Statistical analysis included descriptive statistics, paired t tests, ANOVA, and Pearson's correlations.

Results: In all, 36 participants were randomized (UC, n = 11; GPO, n = 14; lottery, n = 11). Mean percentage (±SD) of days adherent during the incentive period was highest in the lottery group (96% ± 5%), followed by the GPO group (94% ± 9%) and the UC group (94% ± 9%). There were no statistically significant differences among groups (P > 0.05). MEMS-measured adherence was not significantly correlated with a patient's self-reported adherence (P > 0.05) at baseline but was correlated at 90-day follow-up (P < 0.001).

Conclusions: Although no statistically significant differences in adherence were demonstrated in this small sample of highly adherent participants, larger studies in a more diverse population or with other medications might show otherwise.

Keywords: adherence; cardiovascular drugs; clinical trial design; hyperlipidemia; hypertension.