Adolescent sexual behavior: estimates and trends from four nationally representative surveys.

CONTEXT: Accurate information about trends over time in adolescent sexual behavior is essential to understand changes in adolescent pregnancy and sexually transmitted diseases and to monitor the progress of health promotion activities in the United States
METHODS: Estimates from the National Survey of Family Growth (NSFG), the National Survey of Adolescent Males (NSAM), the Youth Risk Behavior Survey (YRBS) and the National Longitudinal Study of Adolescent Health (Add Health) were compared. While methodologies and populations varied by survey, adolescents aged 15-17 who attend high school were a common subpopulation among all four. For each survey, the prevalence of sexual intercourse, contraceptive use and multiple sexual partners was measured in this population.
RESULTS: Trend comparisons fell into four categories. First, some similar significant trends were found across surveys. The proportion of all males and of white males who reported ever having had sexual intercourse decreased significantly, while condom use rose significantly among males in both the NSAM and the YRBS. For such behaviors as ever having had sexual intercourse (among Hispanic males and black females), using the pill and using the condom (among all females) and having four or more lifetime sexual partners (among white males), a significant trend was found in one survey while a similar but nonsignificant trend was found in another. Several trend comparisons were not significant in any survey. Finally, having had intercourse in the past three months (among all males and all females), having had two or more partners in the past three months (for males) and having had four or more lifetime sexual partners (among white females and all males) showed a significant trend in one survey but lacked a parallel nonsignificant trend in another. Prevalence estimates in 1995 differed significantly in at least one comparison of surveys for all behaviors except having four or more lifetime sexual partners (both genders) and having two or more recent sexual partners (females). Gender differences within the YRBS and between the NSFG and the NSAM generally were consistent.
CONCLUSIONS: Trends over time and gender differences were similar across surveys, underscoring their value for tracking adolescent sexual behaviors. Differences in prevalence estimates across surveys probably result from differences in question wording, diverse interview settings and modes of data collection, and varying statistical power. These findings suggest a need to increase our understanding of how methodologies influence survey response in research on adolescents.