ABSTRACT Binge drinking (4+/5+ drinks/occasion for females/males) increases risk for preventable alcohol-related consequences, particularly among young adults (ages 18-25). As part of our NIAAA-funded Mechanisms of Alcohol Treatment Change (MATCH) text message intervention randomized controlled trial (R01 AA023650), we were funded (CTSI pilot) to collect (but not analyze) smartphone sensor (e.g., GPS, communication logs) and Ecological Momentary Assessment (EMA) data on drinking behavior in a MATCH subsample (N=108). This secondary data analysis R21 will leverage the unique combination of phone sensor data collected in the context of an alcohol clinical trial to gain new insight into processes underlying behavior change. Phone sensor data collected during MATCH provides fine-grained objective measures of a person's daily routine in travel pattern and places visited, and sociability (communication pattern). These fine-grained digital traces or digital phenotypes provide objective markers of how a young adult's daily routine (e.g., travel, sociability) changes in relation to response to TM intervention. Phone sensor data provide a means to objectively determine when and how shifts in behavior occur in relation to treatment effects, which will inform phone-sensor-based personal- ization of the next iteration of the digital intervention. Proposed secondary analyses focus on the MATCH subsample (n=93; 71% female, range 18-25]) with EMA data and phone sensor data. Phone sensor (e.g., GPS, accelerometer, communication logs) and EMA data were collected over 14 weeks (2-week run-in + 12- week intervention). The 2-week "run-in" provides a baseline daily "routine" inferred by phone sensors prior to intervention. As in our prior work, we identify intervention "responder" and "non-responder" classes; or explore defining response using reduction in World Health Organization risk drinking level. Aim 1 compares treatment responders and non-responders on digital phenotypes (e.g., travel, communication) prior to TM intervention. Aim 2 compares responders and non-responders on digital phenotypes during TM intervention. An exploratory aim uses group iterative multiple model estimation (GIMME) to simultaneously estimate associations between selected phone sensor features at person-specific (idiographic analysis) and group (responder/non-responder) levels during TM intervention (to complement population-based analyses in Aims 1 and 2). Exploratory analyses provide detailed individual-level information to guide personalization of intervention content, while also indicating associations that are shared at the group-level. Analyses also will explore gender differences, time effects (e.g., weekend/weekday), and treatment arm. These innovative secondary data analyses, which are in line with NIAAA's strategic plan to advance personalized medicine, will (1) determine when and how shifts in young adults' drinking behavior occur in relation to TM intervention, revealing alternative healthy routines in responders; and (2) provide the basis for an R01 project that uses phone sensor data to personalize the recommendation made by an alcohol text message intervention to optimize digital intervention effects.

PROJECT NARRATIVE This secondary data analysis project will use the unique combination of already collected phone sensor data (e.g., activity level, travel pattern, communication pattern from call logs) in the context of an alcohol clinical trial to gain new insight into when and how young adults' routines change in response to alcohol intervention. Phone sensor data provide objective markers of daily routines, which can reveal with low burden, shifts toward alternative behaviors associated with positive response to alcohol treatment. Results will inform personalized interventions based on phone sensor data (e.g., GPS, accelerometer) to optimize digital intervention effects.