Multi-dimensional factors associated with unprotected anal intercourse with regular partners among Chinese men who have sex with men in Hong Kong: a respondent-driven sampling survey

Background: The HIV prevalence and incidence among men who have sex with men (MSM) are high. Unprotected anal intercourse (UAI) with male regular partners (RP) is an important but under-emphasized risk behavior. The current study aimed to describe the prevalence of UAI with regular partner and the associated multi-dimensional factors with UAI among MSM in Hong Kong, China. Methods: Respondent Driven Sampling method was used to recruit participants. A total of 285 participants were recruited, of whom 211 (75.1%) had had anal sex with RP in the last six months and their data were analyzed in this report. Weighed data were presented and logistic regression methods were fit. Results: Participants' high risk behaviors in the last six months included high prevalence of having had UAI with RP (45.8%), having had non-regular male sex partners (NRP: 27.3%) and UAI with such partners (18.9%). Adjusted for socio-demographic variables, factors associated with UAI with RP included: 1) substances use prior to having anal sex (65.7% versus 43.8%; AOR = 2.36; 95% CI = 1.07-5.18), 2) worry that condom use symbolizes mistrust (67.9% versus 44.3%; AOR = 2.91; 95% CI = 1.19-7.10), 3) a lower perceived degree of the RP's acceptance of condom use (91.7% versus 38.3%; AOR = 22.70; 95% CI = 6.20-83.10), and 4) a higher level of impulsivity (61.1% versus 35.0%; AOR = 4.02; 95% CI = 1.62-9.97). Two of these four variables, substances use (ORm = 2.28, 95% CI = 1.01-5.16) and perceived lower level of RP's acceptance of condom use (ORm = 17.22; 95% CI = 5.06-58.62) were selected by the forward stepwise logistic regression model. Conclusions: MSM with RP in Hong Kong is subjected to high risk of HIV transmission. Risk factors of UAI are multi-dimensional and interventions need to take into account factors of structural, interpersonal and individual levels.