A just-in-time adaptive intervention (JITAI) is an emerging mobile health intervention design aiming to provide support “just-in-time”, namely, whenever and wherever support is needed. A JITAI does this via adaptation. The JITAI employs wearable sensors and other approaches to data collection to monitor ongoing information on the dynamics of an individual’s emotional, social, physical and contextual states. The adaptation occurs when this information is used to individualize the type and delivery timing of support. The adaptation in a JITAI is intended to ensure that the right type of support is provided whenever the person is (a) vulnerable and/or in a state of opportunity, and (b) receptive, namely, able and willing to receive, process and utilize the support provided.
We will introduce the micro-randomized trial (MRT), a new trial design useful for addressing scientific questions concerning the construction of highly-effective JITAIs. We will provide an introduction to JITAIs, as well as examples of key scientific questions that need to be addressed in the development of these interventions. We will discuss MRTs and how they can be used to answer these scientific questions. Useful primary aim data analysis methods for MRTs will also be discussed.
The emphasis of this workshop is on JITAI and MRT design considerations and applications. Most of Day 1 and some of Day 2 focus on this. On Day 2, much of the time will be allotted to understanding primary aims in an MRT and conducting associated primary aim analyses.