HIV self-testing secondary distribution among index with different HIV status in China: a pooled analysis of three trials

BACKGROUND: Secondary distribution of HIV self-testing (HIVST) may improve HIV testing coverage and facilitate the diagnosis of people living with HIV, but whether this effect is similar among index men who have sex with men (MSM) with different HIV status is still not clear. METHODS: This study is a pooled analysis of three trials (ChiCTR1900025433, ChiCTR2000039632 and ChiCTR2200064517) conducted by our study team. These three trials aimed to evaluate the effectiveness of monetary incentives in promoting the secondary distribution of HIVST in China. MSM who participated in the three trials were grouped into four groups based on their HIV and intervention status. The control group followed a standard HIVST distribution process in which participants (defined as 'index') distributed the HIVST kits to members of their social network (defined as 'alter'), whereas the intervention group received monetary incentives for promoting altered testing. RESULTS: Between June 2018 and December 2023, 891 unique MSM from 68 cities in China were recruited as index participants, with 55, 54, 390 and 392 categorized into the positive control, positive intervention, negative control and negative intervention groups, respectively. A total of 1035 alters tested for HIV, including 962 motivated by 782 HIV-negative index participants and 73 motivated by 109 index participants living with HIV. The negative intervention group motivated significantly more unique alters to test than the negative control group (IRR 2.46, 95% CI: 1.85, 3.28). With intervention, index living with HIV was less likely to motivate alters for HIV testing (IRR 0.36, 95% CI: 0.23, 0.57). An interaction was not detected between intervention and HIV status. The proportion of newly tested testers among alters was 52%, 48%, 38% and 40% in the positive control, positive intervention, negative control and negative intervention groups, respectively. A total of 41 alters were diagnosed with HIV (5 motivated by index participants living with HIV). CONCLUSIONS: The effect of monetary incentive was lower among MSM living with HIV, even though they tend to identify alters with HIV-reactive results. Integrating incentive-based HIVST secondary distribution into routine HIV prevention and care services is recommended.