Introduction: Sexual risk behaviors (SRBs) often lead to sexually transmitted infections (STI), yet little is known about what drives SRB and whether this differs by sex.
Method: Participants (n = 920; 75% white) were drawn from the Raising Healthy Children study, enrolled in 1993 and 1994 in grades 1 to 2, and followed up through age 24/25 years. Lifetime STI diagnosis was defined by self-report or seropositivity for Chlamydia trachomatis or herpes simplex virus 2. Multivariable models assessed individual (social skills, behavioral disinhibition) and environmental factors (family involvement, school bonding, antisocial friends) predictive of STI diagnosis as mediated by 3 proximal SRB (sex under the influence of drugs or alcohol, condom use, lifetime number of sex partners).
Results: Twenty-five percent of participants had ever had an STI. All SRBs differed by sex (P < 0.001), and female participants were more likely to have had an STI (P < 0.001). Behavioral disinhibition and antisocial friends in adolescence were associated with more SRB for both sexes, whereas social skills were associated with less SRB in female but more in male participants. Considering SRB and individual and environmental factors together, lifetime number of sex partners (adjusted relative risk [ARR], 1.04per partner; 95% confidence interval [CI], 1.03–1.05) and inconsistent condom use (ARR, 1.10per year; 95% CI, 1.04–1.16) were associated with increased risk of STI, whereas social skills were associated with decreased risk of STI (ARR, 0.84; 95% CI, 0.75–0.93). Behavioral disinhibition seemed to drive SRB, but family involvement mitigated this in several cases.
Conclusions: Adolescent environmental influences and individual characteristics drive some SRB and may be more effective targets for STI/HIV prevention interventions than proximal risk behaviors.