Background The iwantthekit (IWTK) internet recruitment screening program began in 2004 and offered an opportunity to determine trends in prevalence for women and men were screened for STIs.

Objectives To determine significance in trends for STIs for the population accessing screening over time.

Methods Participants were recruited via the internet to request home collection kits and to collect either vaginal or penile swabs at home with subsequent mailing to a laboratory for screening for chlamydia (CT), gonorrhoea (GC), and trichomonas (TV) by NAATs. Prevalence for women and men were calculated by year and race for 2004–2011 for each organism. Linear regression analysis was performed to determine significance of temporal trends in gender-, STI-specific prevalence controlling for annual demographic composition of participants.

Results 3363 women were screened for CT and GC from 2004 to 2011; TV screening was added in 2006 (N=2692). From 2006 to 2011, 1370 men were screened for CT, GC, and TV. Prevalence varied: CT: 5.5%–10.6%; GC: 0.3%–2.7%; TV: 5.8%–13.3% for females and CT: 8.0%–15.4%; GC: 0.7%–1.9%; TV: 0.8%–12.4% for males. Most users were from Maryland (70.1%). The only statistically significant linear downtrend by year was CT prevalence in male participants <25 yr from 23.1% in 2007 to 12.5% in 2011, which was 2.4%/yr (p=0.012); while the prevalence in male ¡Ý25 years remained relatively stable from 6.2% in 2007 to 5.5% in 2011 (p=0.911). The remainder of STI prevalences in females and males did not show a downward linear trend by calendar year. GC prevalence in females was significantly correlated with the per cent of Black participants (p=0.030), while TV prevalence in females was positively associated with the number of participants <25 yr (p=0.032).

Conclusions IWTK attracted participants with high-risk sexual behaviours to use home collection for STI testing. Prevalence by year and by organism, for the most part, did not show a significant downward trend.