6 What Makes an Adolescent Sexually Active? Intra- and Interpersonal Influences.

Abstract

Purpose: Sexual abstinence, a healthy people 2010 goal, is a period of time in which a person does not have sex. We examined intra- and interpersonal factors associated with the decision to have sex after a period of abstinence among young women at high STD risk. Methods: With IRB approval, we recruited 378 women (ages 14 – 17 at enrollment, >90% African American) from clinics in high STD risk communities. Subjects (ss) completed face-to-face interviews every 3 months, and daily diaries for 3 month periods twice a year. We PCR tested self-collected vaginal swabs for C. Trachomatis, N. Gonorrhea, and T. Vaginalis every 3 months, and weekly swabs during diary collection. On daily diaries, ss provided partner-specific coital behaviors. We defined an abstinence “run” (consecutive days of no sex) as our unit of analysis. Runs ended with a diary report of sex, and were censored with a missing diary day or the start or end of diary collection. We used frailty models to estimate the effect of intrapersonal factors, interpersonal factors, and STI diagnosis on time to ending a run. Frailty models are adaptations of proportional hazards models that control for multiple observations (in this case “runs” of abstinence) from one individual. Intrapersonal factors included daily positive and negative mood (3 items each, range 3-15, α=0.81 and 0.76 respectively), and daily sexual interest (1 item, range 1-5). Partner-specific interpersonal factors included daily partner support (4 items, range 0-4, α=0.85), and overall relationship quality (6 items, range 6-24, α=0.91). Recent STIs were diagnosed in the quarterly (or 3 month) interview immediately before the run. Results: 378 ss contributed 6070 runs of abstinence, with 55.3% ending with sex and 44.7% censored. The median length of an abstinence run was 10 days (95% CI 9, 11 days) and mean 39.1 days (std error = 0.71). Each year increase in age increased the hazard of ending a run by 22% (p<.001). Each unit increase in sexual interest increased the hazard of ending a run by 22% (p<.001); each unit increase in positive mood increased the hazard by 2% (p<.001); negative mood was not a significant predictor. Each unit increase in partner support increased the hazard of ending a run by 25% (p<.001); and each unit increase in relationship quality increased the hazard by 5% (p<.001). A recent STI decreased the hazard of ending a run by 17% (p<0.01). Conclusions: The decision to have sex after a period of abstinence was strongly influenced by relationship characteristics as well as sexual interest and mood. This challenges popular notions of “casual” adolescent sex (e.g. “friends with benefits”). Adolescent STD prevention may be enhanced by tailoring counseling to these intra- and interpersonal circumstances.