Profiles of Chlamydia Infection Risk Among Urban High School Students

Background: Research suggests that adolescent STD risk is the result of patterns of risk behaviors. However, these studies have largely relied upon self-reported outcomes. This study examines self-reported profiles of sexual risk behavior and lab confirmed chlamydia infection in a sample of urban adolescents.

Methods: Data are from the baseline evaluation of the Project Connect intervention in schools located in the Los Angeles area. Students (N=6,064) completed the survey during a single class period with urine specimen collection typically occurring during the same period. The indicators of sexual risk behavior we used included sex ever, sexual initiation before the age of 14, sex with four or more partners, condom use at last sex, sex in the past three months, casual sex partner at last sex, having a new sex partner in the past 3 months, oral sex ever and in the past three months, anal sex ever and in the past three months, and same sex behavior. Demographic covariates included gender, race and ethnicity, free or reduced lunch, and repeated a grade. Analyses were conducted in R via Bayesian latent class analysis with Gibbs sampling.

Results: A small fraction (1.65%) of the sample tested positive for chlamydia. Based on model examination and previous research, a six class model provided the best fit, including a) an abstinent class (50.8%) with near zero chlamydia risk, b) two classes characterized by high-risk sexual behaviors (23.3%) and 3% chlamydia risk, c) a sexually experienced but not active class with 1% chlamydia risk (10.9%), d) a class characterized by moderate sexual risk behaviors and 8% chlamydia risk (7.7%), and e) a class characterized by high sexual risk behavior with less than 1% chlamydia risk (7.3%).

Conclusions: These findings support previous research suggesting that chlamydia risk is the result of complex patterns of sexual risk behaviors.