1. Condom Use Questions as Predictors of Urogenital Gonorrhea Adrianne M. Williams, MD, Philana Liang, PA-C, MPH, Renee M. Gindi, MPH, Khalil G. Ghanem, MD, and Emily Erbelding, MD Johns Hopkins University School of Medicine and Johns Hopkins Bloomberg School of Public Health

2. Introduction The use of condoms has been shown to decrease the risk of acquiring sexually transmitted infections (STIs). In the clinic setting, clinicians may ask individuals about condom use as one part of a behavioral risk assessment.

3. Introduction One proposed approach to obtaining information about condom use is to ask specifically about use at the last sexual encounter. However, the utility of this approach has not been formally analyzed.

4. Introduction The objective of this study was to examine two different approaches to asking individuals about condom use as a predictor of STI risk. We hypothesized that the response to critical incident condom use (last event use) would be a useful predictor of gonococcal (GC) infection.

5. Methods Records-based historical cohort study We used the electronic medical records of 20,602 individuals who received care at two STD clinics in Baltimore, Maryland, 2004-2005. Risk assessment was completed by structured interview.

6. Methods Example of patient interview: (1) “When was the last time you had sex?” (2) “Did you use a condom?” (3) “Do you use condoms always, often, sometimes, or never?”

7. Methods Patient condom use was recorded in two different ways: (1) Critical incident use: condom use at the last sexual encounter (2) Graded proportional estimate of condom use for all sexual encounters: “always”, “often”, “sometimes”, or “never”

8. Methods All patients had GC culture as part of the standard STD exam –Urethral specimen (males) –Cervical specimen (females) Outcome measure: GC infection as a surrogate indicator of STI/HIV risk

9. Statistical Methods Logistic regression models were used to adjust for known potential confounders (age, race, gender, # of sex partners, known contact to GC). Odds ratios (ORs) and 95% confidence intervals are presented. Data analyses were performed using STATA 8.1 (STATA Corp, College Station, TX).

10. Results (N=20,602) Mean age (IQR) (years)29.6 (21-36) Female (%)42 Race (%) African American Caucasian 92.7 4.4 # Partners last 30 d (%) 1 2-5 >5 66.3 24.7 1.0 Contact to partner w/ GC (%)3.4 Positive GC culture (%)8.5

11. Results: Odds of GC Infection OR adj* (95%CI) Condom use last sex Yes No Reference 1.31 (1.01-1.71) Condom use frequency Always Often Sometimes Never Reference 1.2 (1.0-1.4) 1.1 (0.9-1.2) 0.9 (0.7-1.0) Adjusted for: age, race, # of sex partners, known contact to GC

12. Conclusions Critical incident condom use (last event use) which focuses on a specific event may be predictive of risk of GC infection. Patient report of graded condom use was more difficult to interpret, may be subject to recall bias, and may vary depending upon how the clinician asks the question.

13. Conclusions Strengths: - Critical incident condom use (last event use) is a brief and easy question to ask - Able to validate self-report of condom use with a biomarker (i.e. GC infection) - Able to focus on GC exposed individuals

14. Conclusions Limitations: - Data obtained from clinician-directed interview may not generalize to research setting - Patient interview is not scripted amongst clinicians - Lack of information about partner specificity, i.e. whether condom use is with a regular versus casual sex partner

15. Conclusions Condom use at the last sexual encounter was a reliable measure to discriminate risk of a sexually transmitted infection. The critical incident approach that focuses on behavior at the last sexual encounter was a useful component of risk assessment in the STD clinic setting.

16. Acknowledgements Clinical staff of the Baltimore City Health Department Eastern Health District and Druid Health District STD clinics