The Effect of Interactive Reminders on Medication Adherence: A Randomized Trial

Expanding on evidence that interventions to improve health are more effective when informed by behavioral science, we explore whether reminders designed to harness behavioral science principles can improve medication adherence. We conducted a randomized controlled trial with 46,581 U.S. participants with commercial or Medicare Advantage insurance from Humana. Participants were randomly assigned to one of four experimental conditions. Participants in the usual care condition only received standard mailings that the insurer usually sends. In addition to the standard mailings, participants in the other three conditions also received (1) mailings that reminded them to take a target medication (basic reminder condition), (2) reminders that prompted them to predict their medication adherence in the next 30 days (prediction condition), or (3) reminders that prompted them to commit to a self-determined level of adherence for the next 30 days (commitment condition). We sent these mailings once a month for three months from November, 2014 through January, 2015, and tracked prescription refills. We find that, during the mailing period, reminders increased adherence by 0.95 percentage points (p < 0.05), and this effect was driven by the prediction and commitment conditions; during the three-month post-mailing period, reminders increased adherence by 0.98 percentage points (p < 0.05), and this effect was driven by the basic reminder and commitment conditions. The reminders increased medication adherence by 0.7 pills per dollar spent over our 181 day study period.