Medical interns tend to work long hours, undergo stress, sleep inconsistently, face difficult decisions, and cope with mental health issues during their internship year. There is a critical need to develop interventions to help these interns improve their mood, stay physically active, and sleep consistently. Mobile health interventions (interventions delivered on a phone or mobile device) hold promise because they can be delivered any time at low burden to interns. Unfortunately many questions regarding the design, delivery, and efficacy of these interventions remain unanswered.
In this talk we present a novel trial design for developing and evaluating mobile health interventions, a nested micro-randomized trial. The design is micro-randomized since individuals are randomized hundreds of times throughout the trial. It’s nested because there are several layers of randomizations used to evaluate different intervention components. We discuss advantages of this design and statistical methods for analyzing the trial data and dealing with missing data, a common issue in mobile health studies. The analysis results are presented within the context of 2018 Intern Health Study.