Relationship between gay app use and HIV testing among men who have sex with men in Shenzhen, China: a serial cross-sectional study

OBJECTIVES: To investigate the relationship between gay app use and HIV testing among men who have sex with men (MSM). DESIGN: Serial cross-sectional study. SETTING: A newly well-developed city in China. PARTICIPANTS: 4935 MSM were recruited through offline sampling methods from 2015 to 2017. PRIMARY AND SECONDARY OUTCOMES: The primary outcome is the difference in HIV testing between app and non-app users. RESULTS: 2872 (58.2%) and 2159 (43.7%) participated MSM had been tested for HIV within lifetime and the past year, respectively. Compared with non-app-using MSM, app-using MSM had a significantly higher prevalence of HIV testing within lifetime (adjusted OR (AOR): 1.48, 95% CI 1.27 to 1.72) and the past year (AOR: 1.36, 95% CI 1.18 to 1.57). App-using MSM were more likely to take an HIV test at the Centers for Disease Control and Prevention (AOR: 1.48, 95% CI 1.24 to 1.76) and community-based organisations (AOR: 1.71, 95% CI 1.44 to 2.03), but less often at gay venues (AOR: 0.49, 95% CI 0.37 to 0.63). Meanwhile, app-using MSM were more likely to take self-testing (AOR: 1.61, 95% CI 1.21 to 2.14). Predictors of HIV testing in the past year were: having an education level of college or higher (AOR: 1.29, 95% CI 1.01 to 1.65), being self-identified as a homosexual (AOR: 1.23, 95% CI 1.02 to 1.46), being recruited through clinic-based sampling (AOR: 1.30, 95% CI 1.06 to 1.60), using gay app (AOR: 1.49, 95% CI 1.21 to 1.83), engaging in group sex (AOR: 1.64, 95% CI 1.23 to 2.19), having received HIV-related service (AOR: 5.49, 95% CI 4.57 to 6.60), having a high level of HIV-related knowledge (AOR: 1.33, 95% CI 1.10 to 1.61) and high-risk perception (AOR: 2.95, 95% CI 1.40 to 6.23). CONCLUSIONS: Gay app use was significantly associated with increased HIV testing among MSM hard to reach by traditional outreach. Therefore, it is imperative to expand HIV testing among non-app-using MSM. Continued efforts, innovative strategies and increased resource are highly needed to realise the first ‘90’ target.