Abstract
Despite substantial public and private costs of non-adherence to infectious disease treatments, patients often do not finish their medication. We explore adherence to medication for malaria, a major cause of morbidity and health system costs in Africa. We conducted a randomized trial in Uganda testing specialized packaging and messaging, designed to increase antimalarial adherence. We find that stickers with short, targeted messages on the packaging increase adherence by 9% and reduce untaken pills by 29%. However, the currently used method of boosting adherence through costly, specialized packaging with pictorial instructions had no significant impacts relative to the standard control package. We develop a theoretical framework of the adherence decision, highlighting the role of symptoms, beliefs about being cured, and beliefs about drug effectiveness to help interpret our results. Patients whose symptoms resolve sooner are substantially less likely to adhere, and the sticker interventions have the strongest impact among these patients.