Risk Factors in 6th Grade Predict Health-Risking Sexual Behavior and Lifetime STIs at Age 19

The health and economic consequences of health-risking sexual behaviors (HRSBs), including STIs and unplanned pregnancy are well documented. As such, recognizing and identifying early predictors of subsequent HRSBs and associated negative consequences has the potential to inform relevant prevention strategies with significant public health benefits.

Data on HRSBs and STIs were provided by 1,984 19 year-olds participating in the PROSPER preventive intervention trial targeting substance misuse and related problem behaviors. Age 19 participants were randomly selected for post-high school follow-up from among the 10,849 6th-graders that participated in the baseline assessment conducted in 28 rural Iowa and Pennsylvania school districts.

As part of the post-high school sample selection process, a 6th-grade risk index for later substance misuse was constructed to be used for sample stratification following high school (higher-risk students were over-sampled for follow-up at age 19 and beyond). Participants were classified as either higher- or lower-risk (comprising 37% and 63%, respectively, in the post-high school sample) based on dichotomized indicators of initiation of alcohol or marijuana prior to baseline assessment, level of conduct problems, not living with both biological parents, school lunch program eligibility, and low family functioning.

HRSB was calculated as the sum of 11 dichotomized indicators of sexual behavior collected at age 19 (e.g., number of partners, sex with persons not well-known to the respondent, sex without a condom, sex with an injection drug user). Lifetime STIs was assessed as a dichotomous measure reflecting lifetime diagnosis with any STI.

Regression analyses conducted using SAS PROC MIXED showed 6th-grade Risk to be a robust predictor of both HRSB and Lifetime STIs at age 19. Risk was a significant predictor of HRSBs and Lifetime STIs when modeled as the sole predictor, and across a series of analyses controlling for prevention trial condition, gender, and college attendance. Follow-up analyses examining the separate components comprising the risk index showed each individual risk item also to be a significant predictor of HRSBs and lifetime STIs.

Results highlight the emergence of risk factors in early adolescence that are associated with risky sexual behavior and negative health consequences among young adults. Findings suggest the importance of early intervention to prevent problem behaviors (e.g., early substance initiation) that may portend other health-risking behaviors over the long term, and to provide youth and parent skills-development and supports to address relevant, potentially challenging situational factors, such as those associated with family composition and financial strain.