Limitations
RECRUITMENT
Our study is subject to several limitations. First, the data on recent HIV testing uptake and results were self-reported by participants, which may cause information bias or recall bias. Second, sampling using digital approaches cannot reach people who do not use digital tools frequently. However, offline recruitment and peer recommendation were also used as auxiliary methods, which might alleviate this problem to some extent. Third, 28.3% (n=262) of participants were lost at the last follow-up. We performed a sensitivity analysis adjusting for factors that differed between participants lost to last follow-up and those who finished the last follow-up or seroconverted, and we used multiple imputation to examine the intervention effect. We found the results did not change. Fourth, participants in the intervention arm and the control arm came from different cities in Shandong province. However, the study cities were pair-matched according to their populations, socioeconomic contexts, and HIV burden, which could balance the participants in the 2 arms. Fifth, participants from the intervention and control cities might communicate with each other, resulting in contamination. We conducted per-protocol analyses to measure whether our results were affected by contamination and found the results did not change.