[Factors associated with lost of follow-up of men who have sex with men in a gay bathhouse cohort study in Tianjin, 2012-2015].

To understand the rate of follow-up lost in men who have sex with men (MSM) in a gay bathhouse cohort study in Tianjin and the associated factors. The open cohort study in gay bathhouse was launched in 2012 in Tianjin, and the MSM for baseline survey were recruited from January to June 2012, while the follow up was carried out every six months. A questionnaire survey and HIV test were conducted in the study. The MSM who were HIV negative in the baseline survey in 2012 were used for follow up lost analysis. Univariate and multivariate logistic regression analysis were conducted to identify the factors associated with the lost of follow-up. A total of 658 gay bathhouse patrons were recruited in the baseline survey, at the end of 42-month follow-up period, 173 of them dropped out (26.3%). Multivariate analysis showed that the MSM who were local residents (=0.552, 95: 0.377-0.808), in Han ethnic group (=0.197, 95: 0.066-0.593), having received HIV test in the last year (=0.481, 95: 0.326-0.710), were male sex workers (=0.127, 95: 0.028-0.585), and believed to be at high risk for HIV infection (=0.285, 95: 0.125-0.647). They were more likely to receive follow-up but the MSM who were aged ≥35 years (=1.891, 95: 1.022-3.500) were more likely to be lost in the follow-up. The lost rate of follow-up in MSM in the gay bathhouse cohort was high in Tianjin. Age, household registration, history of HIV test, the awareness of the risk to be infected with HIV and commercial homosex were factors associated with the follow-up rate in the MSM. It is necessary to conduct similar cohort study in targeted population on the basis of findings of this study.