Abstract
BACKGROUND: Nonadherence to diabetes medication is prevalent and costly. MEssaging for Diabetes (MED), a mobile health (mHealth) intervention, identified and addressed user-specific barriers to medication adherence. We assessed whether MED reduced users' targeted barriers and if barrier reductions were associated with within-participant improvements in adherence or glycemic control (HbA1c). METHODS: Adults (N = 80) with type 2 diabetes completed self-report measures identifying barriers to adherence at baseline and monthly for 3 months. At each assessment, 17 barriers were assessed and ranked for each user. Each subsequent month, users received daily text messages addressing their 3 highest ranked barriers. Targeted barriers were different for each participant and could change monthly. Paired t-tests assessed within-participant improvement in targeted barriers each month, and nested regression models assessed if changes in a participant's barrier scores were associated with improvements in adherence and HbA1c. RESULTS: Participants were 69% non-white and 82% had incomes <$25K. Average HbA1c was 8.2 ± 2.0%. Assessment completion rates were 100% at baseline, 59% at 1 month, 30% at 2 months, and 65% at 3 months. The most commonly reported barriers were the cost of medications (76%), believing medications are harmful (58%), and lacking information about medications (53%). Participants' barrier scores improved each month and barrier improvement predicted adherence assessed via nightly adherence assessment text messages ( P < .001). Among participants who completed assessments each month, barrier improvement in months 2 and 3 ( P < .05) predicted HbA1c improvement. CONCLUSIONS: Iterative, individual tailoring may overcome users' barriers to adherence. Attrition is a challenge for mHealth interventions among low-income patients.