Purpose: To explore associations of relationship quality, coital frequency, unprotected coitus, and chlamydia infection over time.
Methods: Data came from 142 adolescent females with sexually transmitted infections attending three primary care adolescent clinics and one county STD clinic. Interview data were collected at 3 time points: enrollment, 1 month, and 3 months after enrollment. Predictor variables included relationship quality, coital frequency, unprotected coitus, and partner change. The outcome variable was infection with C. trachomatis at 3 months. Analyses were conducted using structural equation modeling.
Results: Chlamydia infection at 3 months was directly influenced by unprotected coitus during the previous 2 months (Beta = .25; p < or = .05) and partner change during the enrollment/1-month interval. Unprotected coitus was directly associated with coital frequency, both cross-sectionally and longitudinally. Increased relationship quality was associated with increased coital frequency but did not have direct effects on unprotected coitus.
Conclusions: The data showed a protective effect of condom use for chlamydia infections. Prevention efforts should attend to the interpersonal factors behind decisions to use or not use condoms.