To determine whether a measure of unprotected vaginal sex that is adjusted for condom failures would produce improved accuracy in predicting biologically confirmed STDs (chlamydia and gonorrhea) among female teens.
Self-reported measures were collected using audio-computer-assisted self-interviewing. DNA amplification for the presence of Chlamydia trachomatis and Neisseria gonorrhoeae was conducted.
The unadjusted measure of unprotected vaginal sex was not significantly associated with biologically confirmed prevalence of STDs (prevalence ratio [PR] = 1.51; 95% CI = 0.71–3.21; P = 0.28). Alternatively, the adjusted measure achieved significance (PR = 3.59; 95% CI = 1.13–11.38; P = 0.014). More than one quarter (25.6%) of teens using condoms inconsistently and/or incorrectly tested positive for an STD compared to 7.1% among those reporting the consistent and correct use of condoms.
Findings demonstrate that studies of condom effectiveness should use an adjusted measure of condom use to achieve precision and rigor.
Findings from a study of teen females suggest that accounting for condom failures may substantially add to the rigor of studies designed to test condom effectiveness.
From the *College of Public Health, University of Kentucky, Lexington, Kentucky; †Rollins School of Public Health, Emory University, Atlanta, Georgia; ‡Rural Center for AIDS/STD Prevention at Indiana University, Bloomington, Indiana; §Emory University School of Medicine, Department of Pathology and Laboratory Medicine (Infectious Diseases), Atlanta, Georgia; ¶Emory University School of Medicine, Department of Pediatrics, Atlanta, Georgia; ∥Kinsey Institute for Research in Sex, Gender, and Reproduction, Bloomington, Indiana; #Applied Health Science and Gender Studies at Indiana University, Bloomington, Indiana; and the **Georgia Department of Juvenile Justice, Atlanta, Georgia
This research was supported by the Emory Center for AIDS Research (NIH/NIAID 2 P30 AI50409–04A1).
Correspondence: Richard Crosby, PhD, College of Public Health, University of Kentucky, 121 Washington Ave., Room 111C, Lexington, KY 40506-0003. E-mail: firstname.lastname@example.org.
Received for publication November 8, 2004, and accepted January 11, 2005.