O2-S3.04 Web-based sex diaries and young men who have sex with men: assessing feasibility, reactivity, and data agreement

Abstract

Background: Web-based diaries are a promising means for collecting detailed sexual behaviour and substance use data. Few studies have evaluated the feasibility and reliability of collecting these data among men who have sex with men (MSM). We compared quantitative diary data with retrospective survey data collected over 1- year in a cohort of young MSM in Seattle, WA. Methods: Ninety-five MSM, age 16-30, completed web-based surveys every 3 months and were randomised to 1 of 4 diary submission schedules: every 2 weeks, once a week, twice a week, or never. The diaries asked questions about daily sexual behaviour and substance use. We assessed the agreement between diary and survey data using statistics for dichotomous variables and concordance correlation coefficients (CCC) for continuous variables. We used generalised estimating equations to assess for differences in survey data over time between those assigned an active diary schedule to those assigned no diary. Results: During the first 6 months, 78% of participants assigned to an active diary schedule completed at least 80% of their diary days, and the 2-week schedule had the highest and most consistent completion rate. Completion rates dropped to <60% during the second 6 months. Among participants with active diary schedules, most measures had strong agreement between the diary and survey data (ie, or CCC>=0.8). The exceptions to this were numbers of overall and unprotected anal sex acts during the first 3 months (CCC=0.53 and 0.57, respectively) and alcohol use during the first 6 months (=0.57-0.59). We observed some reactivity, or a difference in reported behaviour associated with diary completion. For example, participants assigned no diary reported an average increase of 5.2 more unprotected anal sex acts over consecutive 3-month periods than those assigned an active diary schedule (p<0.01). Conclusions: This study suggests that sexual behaviour and substance use data collected from young MSM during 3-month retrospective surveys-an interval commonly used in sexual behaviour research-are largely adequate. Web-based diaries can be used for up to 6 months to gather detailed behavioural data, and may be more appropriate than retrospective surveys for counts of anal sex acts. Furthermore, our finding that diaries may be associated with lower levels of reported sexual behaviour suggests that web-based diaries may be useful as a behavioural intervention to prevent HIV/STI among young MSM.