SHEW, MARCIA L. MD, MPH*§; REMAFEDI, GARY J. MD, MPH*; BEARINGER, LINDA H. PHD, MS, RN*†§; FAULKNER, PATRICIA L. MS*; TAYLOR, BARBARA A. MPH, RN[//]; POTTHOFF, SANDRA J. PHD‡§; RESNICK, MICHAEL D. PHD*‡§

Background: Research and public health interventions designed to reduce the risk of sexually transmitted diseases (STDs) often are based on self-reported condom use. Yet, validation of self-reported condom use, in particular with adolescents, has rarely been described in the literature.

Methods: Baseline data were obtained from 540 adolescents, 13-21 years of age, enrolled in a 1-year longitudinal study of health beliefs, sexual behaviors, and STD acquisition. Of the 445 participants reporting to be sexually active, 404 (90.8%) agreed to a complete physical examination, including a genital examination, with STD screening after completing the self-administered written questionnaire. Participants' written self-report of condom use was compared to histories obtained by clinicians and laboratory diagnosis of acute STDs to assess validity of written self-report.

Results: Complete data were available for 321 females and 77 males of whom 52 females and 5 males had laboratory evidence of 63 infections. Although three individuals who had STDs reported to be consistent users of condoms, a significant association (P < 0.05) was found between those who reported more frequent condom use with the last two partners and the absence of STDs.

Conclusion: In this group of adolescents, self-report of condom use with the last two partners was associated with the absence of an acute STD. This finding suggests that self-reported condom use is a valid indicator of risk for STDs, with implication for those working with adolescents clinically and in research contexts.

NATIONAL INDICATORS consistently show that teenagers in the United States are becoming better users of condoms, although inadequate use rates continue to threaten the health of the adolescent population. This response of increasing condom use was probably secondary not only to the risk of human immunodeficiency virus (HIV) but to increasing rates of gonorrhea in 15 to 19 year olds (despite declining rates in adults) in the 1980s 1; reported prevalence rates of chlamydia as high as 25% in various populations of adolescents 2; and an increase in birth rates among adolescent girls starting in 1988 after a decade-long trend of decreased birth rates,3 although birth rates are again declining. In 1988, reported condom use at last intercourse was 57.5% in males 17 to 19 years old and 47.4% in females ages 15 to 19 years by reports of use at first intercourse.4,5 Both these figures showed increased rates from 1981 but clearly were associated with increasing rates of sexual activity in teens. Based on the Centers for Disease Control's 1993 in-school surveys of risk behaviors (YRBS), 53.0% of 9th through 12th graders reported ever having intercourse. Of these, 52.8% reported that they or their partner had used a condom during last sexual intercourse.6 Use of condoms at last intercourse by sexually active students varied from 27.6% to 59.6% in different states, but the consistent use of condoms was far less prevalent, as corroborated by other research.7 National figures show a trend toward safer sexual practices, yet they are based solely on self-report data, the validity of which has not been adequately assessed.

Latex condoms have clearly demonstrated in vitro activity against bacterial and most viral sexually transmitted diseases, including gonorrhea, chlamydia, syphilis, herpes, and HIV infections.8-10 Clinical data indicate that condoms are efficacious against bacterial and viral sexually transmitted diseases. Cross-sectional and case-controlled studies in adult populations have demonstrated that self-reported condom use is associated with lower rates of HIV, herpes simplex, trichomonas, pelvic inflammatory disease, gonorrhea, and chlamydia infection,11-14 although the magnitude of protection varies. Failure rates of condoms generally are thought to be a result of inconsistent use and, to a lesser extent, breakage.12 Again, however, assessment of the efficacy of condom use has relied on self-reported data.

Not only is our optimism about the increasing prevalence of condom use based on self-reported data, but so too are preventive interventions. Clinical interventions, aimed at reducing rates of STDs among at-risk persons, often target those who report no or minimal condom use. This approach assumes that self-reported condom use accurately reflects true behavior and is a valid indicator for risk of STD acquisition. In the last three decades, many studies have examined the test-retest reliability of self-reported condom use at the individual level,12,15 but few have studied the validity of self-reported condom use, i.e., the extent to which self-report reflects actual behavior.16-18 Even fewer studies have combined clinical interview or paper-and-pencil questionnaire with biologic markers to assess the validity of self-reported condom use.19,20 Most of these reports were derived from adult populations, with some including small numbers of adolescents.

This study was undertaken to examine the validity of adolescents' reported condom use in relation to condom use, self-efficacy, and laboratory diagnosis of acute STDs. We examined which dimensions of condom use (with last partners, ever use, annual and monthly consistency, and duration of use for the last year) were associated with STDs. Specifically, it was hypothesized that self-reports of condom use on paper-and-pencil questionnaires would correlate with (1) condom use self-efficacy, (2) verbal reports to clinicians, and (3) documented acquisition of an STD.

The present analysis used baseline data collected in 1989 and 1990 from a 1-year longitudinal study of health beliefs, sexual behaviors, and STD acquisition and recidivism among 540 adolescents, ages 13 to 21 years. All participants were recruited from school and community-based clinics in the St. Paul metropolitan area. Overall study enrollment rates were high, with more than 90% of those eligible agreeing to participate. Study protocols were approved by the Institutional Review Board (IRB) at the University of Minnesota. Written, informed assent/consent was obtained from all participants in the study. In light of the Minnesota Medical Bill for Minors Act, which permits adolescents to use clinics confidentially for reproductive health concerns, parental consent was not deemed necessary by the IRB.

Study participants completed a detailed self-administered questionnaire (Youth Behavior and Health Survey, available on request) tapping demographic information; sexual knowledge, beliefs, and behaviors; contraceptive use; and history of STD testing and diagnosis. Those who reported ever having oral, vaginal, or rectal intercourse in the written survey were invited to participate in a free physical examination and STD screening. Individuals were excluded if they had systemic antibiotic therapy in the previous 6 months or if they had STD screening within the last month since both could alter STD results. The choice of a 6-month time frame was based on a balance of factors: the risk of missing infections incurred and treated between entry and conclusion of the larger longitudinal study versus the risk of limiting the sample size with a longer exclusionary period. The 6-month exclusionary period also was consistent with prior research examining risk factors for STDs.21 Before the physical examination, information was obtained by the clinical examiner (physician or nurse) in a face-to-face structured interview about contraceptive and pregnancy history, history of STDs, STD-related symptoms, and pregnancy outcomes. Specifically, clinicians asked about ever use of condoms, duration of use in the last year (in months), and consistency in the past year and past month (sometimes, usually, always). Partner-specific condom use was only obtained through written self-report. Those who agreed received a complete physical examination, including a pelvic examination for females and a genital examination for males.

All eligible adolescents were screened for cervical (females) or urethral (males) Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis. Samples for N. gonorrhoeae were directly inoculated onto Thayer-Martin media, whereas specimens for C. trachomatis were obtained with a cotton-tipped metal stick that was placed in transport media for culture in McCoy cells. Urine sediment from males and vaginal discharge from females were cultured for T. vaginalis in STS media. Rectal and/or pharyngeal cultures were obtained for gonorrhea and chlamydia from subjects who reported oral or rectal intercourse or signs or symptoms of infection.

Although some STD screening was done for human papillomavirus, HIV, and herpes simplex virus, current analyses are limited to acute STDs, because clinical latency periods for viral STDs can be highly variable. All adolescents who were found to have STDs were treated, and identifying information was reported with the adolescents' knowledge and cooperation to the Minnesota Department of Health in accordance with state law. Subjects received a $5 reimbursement for completion of the questionnaire, and those who otherwise would not be receiving STD screening as part of their visit were reimbursed $20 for the examination.