Trends in sexual risk behaviors, by nonsexual risk behavior involvement, U.S. high school students, 1991-2007.

BACKGROUND: Adolescent health risk behaviors often occur together, suggesting that youth involvement with one risk behavior may inform understanding of other risk behaviors. We examined the association between involvement in nonsexual risk behaviors and trends among sexual behaviors.
METHODS: We analyzed 1991-2007 data (n = approximately 125,000) from the Youth Risk Behavior Survey, a nationally representative survey of high school students in the United States. We categorized students into groups based on lifetime (Lifetime Risk Scale) and recent involvement (Recent Risk Scale) in nonsexual risk behaviors, such as smoking and drug use. We examined each group's prevalence of and trends for four sexual behaviors: ever having had sexual intercourse, having four or more lifetime partners, current sexual activity, and use of contraception at last sex. Data were examined for linear and quadratic (U-shaped) change using logistic regression.
RESULTS: Sexual behaviors varied considerably between youth engaged in no risk behaviors and those in the highest risk behavior groups: sevenfold for ever having had intercourse (13% vs. 87% in 2007) and threefold for four or more lifetime sexual partners (19% vs. 57%). Despite these differences, trends in sexual risk behaviors among youth engaged in multiple nonsexual risk behaviors and those engaged in few or no risk behaviors were remarkably similar. In contrast, sexual behaviors demonstrated a very different pattern of change from that found or nonsexual behaviors: sexual experience and having multiple sexual partners declined into the early 2000s and then increased, whereas nonsexual behaviors increased over time, peaked in the late 1990 s, and then declined.
CONCLUSIONS: Youth who engaged in little risk taking and those who engaged in considerable risk taking showed similar trends over time. However, the pattern of changes in sexual and nonsexual risk behaviors were remarkably different, raising questions about the potential impact of interventions that would reduce sexual risk taking by reducing nonsexual risk behaviors. Recent increases in sexual risk behaviors may have ominous implications for prevention of unplanned pregnancy and sexually transmitted infections among youth.