Comparing the effectiveness of secondary distribution of HIV/syphilis dual self-testing to testing card referral in promoting HIV testing among gay, bisexual, and other men who have sex with men in Guangzhou, China: a quasi-experimental study

Background Social network approaches to testing allow individuals (indexes) to distribute tests to social networks (alters). This quasi-experimental study compared two social network-based testing strategies in promoting human immunodeficiency virus (HIV) testing among Chinese gay, bisexual, and other men who have sex with men (GBMSM). Methods GBMSM aged >= 18 years were recruited from Guangzhou, China. From May to September 2019, indexes could distribute blood-based HIV/syphilis dual self-testing kits to people within their social network. Indexes recruited from October 2019 to January 2020 could send HIV testing cards to their social networks for free facility-based tests. Alters were encouraged to upload a photo verification of test results. Indexes and alters received incentives during both periods. Results There were 245 participants who were assessed for eligibility and 208/245 (84.9%) were eligible. 106 and 102 indexes were recruited in the secondary distribution and testing card arms respectively. 154/208 (74.0%) completed follow up at 1 month. 92 indexes in the secondary distribution arm self-reported distributions to 179 unique alters, and 62 in the testing card arm to 26 unique alters. An average of 1.95 (standard deviation [s.d.] = 1.90) HIV/syphilis dual self-tests and 0.42 (s.d. = 0.78) HIV testing cards were distributed, generating a risk difference of 1.53 (95% confidence interval [CI] 1.09, 1.96). Indexes self-identifying as gay (P = 0.007) or having previously tested (P = 0.02) distributed more tests. Secondary distribution cost less per alter tested (USD120 vs USD9408). Conclusions Secondary distribution engaged more GBMSM to distribute tests and reached more GBMSM to test compared to referral cards, suggesting advantage in facilitating testing uptake among Chinese GBMSM.