Participants
syphilis, Media, MSM
SYPHILIS, RECRUITMENT
The full study protocol has been published previously (Wang et al., This was a three-arm, non-blinded, parallel individually randomized controlled trial among MSM. Enrolled indexes were randomly assigned in a 1:1:1 ratio into three arms: standard-of-care arm (SOC arm); standard SST delivery arm (S-SST arm); and a web-based referral link SST delivery arm (RL-SST arm where a referral link is used to apply online for free SST packages) (Fig. Key concepts of the three study arms. *SOC arm: standard-of-care arm; S-SST arm: standard syphilis self-testing delivery arm; RL-SST arm: referral link syphilis self-testing delivery armWe enrolled index cases who were seeking HIV testing at the study sites by advertising the recruitment in the CBOs’ social media platform, including WeChat (Tencent Inc., Shenzhen, China) group chats and public account, as well as BlueD (Beijing Bluecity Culture and Media Co., Ltd., China). WeChat is the most popular instant messaging application in China, while BlueD is the most popular social networking application among MSM in China. Research staff conducted the recruitment at the partnered organization sites. All participants were asked for their willingness to pass along the information packages or SST packages to their peers and screened for eligibility when they took the survey. Inclusion criteria were: born biologically male, aged 18 or above, have ever had sex with a man, willing to refer the intervention tools to peers, and willing to take the follow-up survey in three months. Eligible participants then entered the survey through a QR code. Digital informed consent was required for every participant at the baseline survey. All participants administered the survey by themselves with assistance from the research staff if needed. We reported our findings according to the Consolidated Standards of Reporting Trials (CONSORT) guidelines (Appendices pp. 18–20).