Data collection
All men in both trials were encouraged to upload their HCV testing record and results. HCV self-testing was determined by photo verification of the used test kit, while facility-based HCV testing and results were determined by photo verification of the test report. Men who uploaded photo verification were provided with US$1.All participants completed a baseline questionnaire at enrollment, including socio-demographic characteristics, sexual behaviours, knowledge of HCV, stigma associated with HCV, attitudes towards people living with HCV, and HIV/STI testing experiences. The follow-up survey collected information on HCV testing and other STI testing experiences in the past 4 weeks. Participants were provided with a compensation of US$4 for completing the follow-up survey.