Our previous pilot study during 2010-2013, based on the IWantTheKit (IWTK) home self-collection program for sexually transmitted infections (STIs), showed that voluntary risk score tool predicted STIs well in female volunteers compared to their male counterparts. Risk score became a required part of the IWTK program in August 2013. We investigated association of IWTK risk score and presence of STI in 592 male participants living in Maryland and Washington DC from August 2013 to April 2015. The risk score quiz includes questions on demographic and sexual risk behavior. Data were analyzed using the Cochran-Armitage test for trend to determine if prevalence of STIs (Chlamydia, gonorrhea, or trichomoniasis) increased with the higher risk score category. Overall, 57% of participants were aged < 30 years (mean: 30.1 ± 9.3 years); 42% white, 42% black, and 16% other races. The majority (67%) of participants had medium risk scores of 3-6, followed by high scores of 7-10 (22%), and 0-2 (11%). The overall prevalence of STIs was 10.5% (62/592). The prevalence of STIs was 3.1% for users with risk scores of 0-2, 10.4% for those with scores 3-6, and 14.3% for those with scores 7-10 (trend test: p = 0.019). Medium and high IWTK risk scores successfully predicted the probability of STIs in male participants after elimination of potential selection biases.
Keywords: Chlamydia; Sexually transmitted infection screening; gonorrhea; internet-based recruitment; men; risk score; trichomoniasis.