Abstract
BACKGROUND: text-messaging systems have been used to promote a range of health behaviors, including medication adherence among human immunodeficiency virus-positive individuals. However, little is currently known about the specific characteristics of messaging systems that promote user engagement. OBJECTIVE: using data from a randomized controlled trial involving a pager-based text messaging system, this study sought to examine the overall usability of the system, user evaluation of the system, demographic and psychosocial correlates of usability, and its performance as an adherence assessment tool. MATERIALS AND METHODS: the messaging system consisted of an alphanumeric pager capable of sending and receiving individualized text messages and the software necessary to program and track communication. The system was evaluated using behavioral outcomes (pager message response rate), self-report survey responses, focus group discussions, and data from electronic medication monitoring pill bottles. RESULTS: Although the majority of participants reported that the system was effective in reminding them to take medication doses, the overall response rate to system messages was relatively low (42.8%) and dropped significantly over the course of the 3-month intervention period. In addition, user engagement did not differ significantly by most demographic and psychosocial variables. CONCLUSIONS: the pager-based text messaging system was received well by participants and appears to be applicable to a broad population; however, the system did not actively engage all participants over the course of the trial. Future research should determine whether systems customized to personal preference in notification style, frequency, and user device can increase use and provide further assistance to achieve optimal medication adherence.