Objective: This pilot micro-randomized trial (MRT) evaluated feasibility of the MRT design and compared acceptability and preliminary impacts of drinking-focused and maternal-focused text messages to inform development of a tailored just-in-time adaptive text messaging intervention for postpartum at-risk alcohol use.
Method: Postpartum mothers (n = 65) participated in a 28-day MRT. Participants completed ecological momentary assessment (EMA) surveys upon waking (morning survey) at two random times daily (hourly surveys), with an optional night survey (night survey). After each hourly and night survey, participants were randomized to receive either a maternal-focused message, a drinking-focused message, or no message. Check-in surveys assessed intermediate (motivation, maternal self-efficacy, drinking self-efficacy, self-regulation, and craving) and primary (alcohol use) outcomes 15 minutes later.
Results: Compliance rates for all survey types exceeded 70%, except for optional night surveys. Participants reported low burden associated with the MRT. Participants were more likely to rate maternal-focused messages as helpful and evoking positive feelings compared to drinking-focused messages. A significant effect of receiving an intervention message (vs. no message) was found for drinking self-efficacy (DSE), with those who received a message reporting higher DSE compared to those who received no message, with no difference between message types. Significant time by condition interactions revealed that the effect of maternal messages decreased over time, while DSE increased over time for the control condition.
Conclusions: Findings support feasibility and acceptability of the MRT design in postpartum mothers with at-risk drinking histories and inform the development of a tailored text messaging intervention for this population.