Do Diary Studies Cause Behavior Change? An Examination of Reactivity in Sexual Risk and Substance Use in Young Men Who Have Sex with Men

Behavioral diaries are frequently used for observing sexual and substance use behaviors, but participating in diary studies may cause behavior change. This study examined change in sexual and substance use behaviors among young men who have sex with men (YMSM) in a two-month diary study compared to control. An analytic sample of 324 YMSM was randomized to receive daily diaries, weekly diaries, or no diaries (control) for 2 months. Half of the diary participants were randomized to receive automated weekly feedback. Between-subjects analyses found no evidence of change in sexual or substance use behaviors from baseline to 2-month follow-up when comparing the diary conditions to control. Within-persons growth mixture models of all diary data showed significant decreases in condomless anal sex (CAS) and illicit drug use. Weekly automated feedback had no effect on behavior change. Findings provide evidence of change in CAS and illicit drug use amongst diary participants.