Pilot feasibility study of Heart2HAART: a smartphone application to assist with adherence among substance users living with HIV

Background: Smartphones with programmable apps may offer innovative interactive interventions for improving adherence among people living with HIV with substance use problems. Methods: This pilot randomized controlled trial sought to primarily determine the usability and feasibility of using a smartphone-based intervention called Heart2HAART as an adjunct to directly observed treatment with adherence counseling compared to directly observed treatment with adherence counseling alone among those with HIV and a history of substance use over a three-month time frame. Participants in the Heart2HAART condition completed an additional survey on usability and acceptability. Adherence was measured using unannounced pill counts assessed via a phone call. Results: Twenty-eight participants were randomized to receive Heart2HAART (n=19) or control (n=9). All were receiving either weekly (n=9) or daily (n=19) observed treatment. Among those randomized to Heart2HAART, 63.2% reported no difficulty using the Heart2HAART smartphone application and 94.7% responded that the medication reminders did not interfere negatively with their activities. On average participants used Heart2HAART application 56.8 times over the three-month trial. In analyses adjusting for age, there was no difference in adherence to HAART medication between the Heart2HAART and control group as evaluated by the random pill count assessment (P=.29). Conclusions: Heart2HAART was feasible to use during a three-month pilot trial. Future studies may evaluate a more tailored approach, with more robust contingency management.