We utilized user-centered design (UCD) methods to iteratively develop the DIAMANTE content and text messaging system through three iterative phases of UCD with ten patients each (total n=30). The first phase consisted of 1.5-hour individual semi-structured interviews. Findings from phase 1 were used to inform content and information delivery decisions of the final intervention, including selecting the thematic message categories and the design. In the second phase, patients tested out an early prototype of the mobile application through usability testing. Patients tested the final DIAMANTE intervention including thematic message content and the application in the third, final UCD phase, in order to address any user-related issues prior to launching the randomized control trial.
In the DIAMANTE Randomized Controlled Trial, we aim to examine the effect of a smartphone app that uses reinforcement learning to predict the most effective messages for increasing physical activity. We will recruit 276 low-income minority patients with depression and diabetes within he San Francisco Health Network. We will compare this intervention to static messages with health management content, and a control group that only receives a weekly mood message.
