Cell phone-based ecological momentary assessment of substance use context for Latino youth in outpatient treatment: Who, what, when and where.

BACKGROUND: Relationships between alcohol, marijuana and other drug (AOD) use and contextual factors have mostly been established through retrospective self-report. Given the embeddedness of cell phones in adolescents' daily activities, cell phone-based ecological momentary assessment (CEMA) provides an opportunity to better understand AOD use in youth and how cell phones can be used to self-monitor and deliver interventions. We use CEMA to examine AOD use in Latino youth who have been especially understudied. METHODS: Twenty-eight mostly Latino youth (ages 13-18) in outpatient substance abuse treatment recorded AOD use, contextual factors, cravings, and affect through once-daily CEMA over one month periods. Random-effects logistic regression was used to compare contextual factors between periods of AOD use and non-use. RESULTS: The most frequent contextual factors reported during AOD use were being with close friends and "hanging out" as the primary activity. During AOD use compared to non-use, youth were more likely to be with close friends (OR=4.76; p<0.01), around users (OR=17.69; p<0.01), and at a friend's house (OR=5.97; p<0.01). Alcohol use was more frequently reported at night (63% vs 34%) and on weekends relative to other substances (64% vs 49%). Strong cravings were more frequently reported on AOD-use days (OR=7.34; p<0.01). Types of positive and negative affect were reported with similar frequencies, regardless of AOD use. CONCLUSIONS: Reporting on social context, location, day and time of day, and cravings all show promise in developing cell phone-based interventions triggered by contextual data.