Validity of Partner Reports of Recent Condomless Sex.

BACKGROUND: Prostate-specific antigen (PSA), a biomarker of vaginal semen exposure, is less susceptible to bias than self-reported condom use behaviors. We examined the agreement of self-reported recent condomless sex (RCS) within couples and how these reports related to PSA detection. METHODS: We analyzed data from a study conducted in Vietnam, 2017 to 2020, of 500 different-sex couples using condoms and no other contraceptive method to prevent pregnancy for 6 months. We assessed enrollment and 6-month data from vaginal swabs and questionnaires from both partners. We calculated Prevalence-Adjusted Bias-Adjusted Kappa (PABAK) to evaluate agreement of men's and women's reports. Among couples with detected PSA, we assessed partner concordance of RCS reporting. RESULTS: At enrollment (n = 499), 79.8% of couples reported no RCS, 16.4% reported RCS, and 3.8% had partner-discordant reports (PABAK, 0.93; 95% confidence interval, 0.91-0.97). At 6 months (n = 472), 91.7% reported no RCS, 5.7% reported RCS, and 2.5% had partner-discordant reports (PABAK, 0.98; 95% confidence interval, 0.96-1.0). Among couples with detected PSA at baseline (11%, n = 55), 36% reported no RCS, 55% reported RCS, and 6% had discordant reports; at 6 months (6.6%, n = 31), 58% reported no RCS, 35% reported RCS, and 3% had discordant reports. CONCLUSIONS: We observed high agreement regarding condomless sex within couples in a population using condoms as contraception in Vietnam; however, a high proportion of couples with detected PSA had both partners reporting no RCS, indicating that concordant reporting of no RCS does not indicate lack of semen exposure.

Effectiveness of erectogenic condom against semen exposure among women in Vietnam: Randomized controlled trial.

A key barrier to the consistent use of condoms is their negative effect on sexual pleasure. Although sexual pleasure is a primary motivation for engaging in sex and is an integral part of overall sexual health, most programs to improve sexual health operate within a pregnancy and disease-prevention paradigm. A new condom, CSD500 (Futura Medical Developments; Surrey, UK), containing an erectogenic drug was developed for use among healthy couples to improve sexual pleasure by increasing penile firmness, size and erection duration. We conducted a randomized controlled trial to test whether promoting the novel condom CSD500 for improved sexual pleasure is effective in reducing condomless sex compared to the provision of standard condoms with counseling for pregnancy and disease prevention. We randomized 500 adult, heterosexual, monogamous couples in Thanh Hoa province, Vietnam to receive either CSD500 (n = 248) or standard condoms (n = 252). At enrollment and after 2, 4, and 6 months, we interviewed women and sampled vaginal fluid to test for the presence of prostate-specific antigen (PSA), an objective, biological marker of recent semen exposure. We registered the protocol before trial initiation at ClinicalTrials.gov (identifier: NCT02934620). Overall, 11.0% of women were PSA positive at enrollment. The proportion of follow-up visits with PSA-positivity did not differ between the intervention (6.8%) and control arms (6.7%; relative risk, 1.01; 95% confidence interval, 0.66-1.54). Thus, we found no evidence that promoting an erectogenic condom to women in a monogamous, heterosexual relationship in Vietnam reduced their exposure to their partner's semen. These findings might not hold for other populations, especially those with a higher frequency of condomless sex.