Effects of an Internet-based intervention for HIV prevention: the Youthnet trials

Abstract

Youth use the Internet and computers in unprecedented numbers. We have yet to identify interventions that can reach and retain large numbers of diverse youth online and demonstrate HIV prevention efficacy. We tested a single session condom promotion Internet intervention for 18-24 year olds in two RCTs: one sample recruited online and one recruited in clinics. All study elements were carried out on the Internet. Using repeated measures structural equation models we analyzed change in proportion of sex acts protected by condoms (PPA) over time. Among sexually active youth in the Internet sample, persons exposed to the intervention had very slight increases in condom norms, and this was the only factor impacting PPA. We saw no intervention effects in the clinic sample. Internet-based interventions need to be more intensive to see greater effects. We need to do more to reach high risk youth online and keep their attention for multiple sessions.

Figure 1

*407 removed from online sample at f/u who had never had sex (N=242), had multiple inconsistencies in responses (N=53); and/or had >=one items missing on dependent or independent variables (N=112). 311 persons were removed from the clinic sample analyses who were either not sexually active at baseline (N=13), had missing data (N=232) or data inconsistencies (N=66)

Figure 2

Figure 3

A Priori Theoretical Model describing relationships between predictors of condom use and proportion of protected sex acts

Figure 4

Outcomes, Internet Sample and Clinic Sample