169-LB: A Randomized Encouragement Trial to Increase Mail Order Pharmacy Use and Medication Adherence

Medication non-adherence is a major contributor to poor diabetes outcomes. Observational studies show positive associations between mail order pharmacy (MOP) use and adherence, and suggest that mail order is cost-saving to patients. However, no prospective trials have examined the effect of encouraging MOP use on medication adherence. We conducted a randomized encouragement trial in 2017 in three health plans: Kaiser Permanente (KP) Northern California, KP Hawaii, and Harvard Pilgrim Health Care (HPHC). Patients were eligible if they had diabetes, poor adherence (Proportion of Days Covered <80%) to at least one class of cardiometabolic medications, and had not used MOP in the prior 12 months. Patients were randomized to receive either no intervention (controls) or outreach encouraging MOP use consisting of a mailed letter, secure email message, and automated telephone call outlining the potential benefits of MOP use for diabetes patients; HPHC intervention patients received the letter only. We compared the percentages of patients in both arms that began using mail order and that became adherent to cardiometabolic medication classes during the 12-month follow-up. A total of 63,012 patients were included: mean age was 60; 45% were female; 41% were non-Hispanic white; 12% were black; 25% were Hispanic/Latino, and 22% were Asian/Native Hawaiian/Pacific Islander. During follow-up, 12% of intervention patients used the mail order pharmacy vs. 10% of controls (p<.001); the percent of cardiometabolic medications delivered via mail was 42% vs. 39% (p<.01). Metformin adherence improved in the intervention group relative to controls at the two KP sites (52% vs. 49%, p<.01). This randomized trial shows that simple outreach to encourage MOP use modestly improved its use, and improved adherence to a key class of diabetes medications in some settings. Clinicians and health systems should consider such low-cost interventions to actively promote MOP among diabetes patients.