Bias in Self-Reported Condom Use: Association Between Over-Reported Condom Use and Syphilis in a Three-Site Study in China.

Abstract

This study examined over-reporting bias in self-reported condom use and assessed its association with syphilis. A survey was conducted among 1245 female sex workers (FSWs) in three cities in China. Respondent's over-reported condom use was defined as reporting no unprotected sex for the past 24h but testing positive for prostate specific antigen. The proportion of prevalent syphilis and active syphilis was 23 and 10% respectively among FSWs. The proportion of over-reported condom use with sex clients only was 27-45% among the three study sites. The proportion of over-reported condom use with all sex partners (clients, husbands, or boyfriends) was 26-46%. FSWs who had active or prevalent syphilis were more likely to over report condom use. Self-reported condom use may not be a valid tool to measure the efficacy of HIV/STI intervention because the bias is associated with the outcome measure, i.e., syphilis.