The impact of a syndemic theory-based intervention on HIV transmission risk behaviour among men who have sex with men in India: Pretest-posttest non-equivalent comparison group trial.

This study aimed to examine the effect of a syndemic theory-based intervention to reduce condomless anal intercourse among men who have sex with men (MSM) in India. In 2016/17, a pre- and post-test comparison group design was used to implement a syndemic theory-based intervention among 459 MSM (229, intervention; 230, standard-of-care comparison) recruited through non-governmental organizations in Chandigarh, India. The intervention group received two-session peer-delivered motivational interviewing-based HIV risk reduction counselling and skills training to improve sexual communication/negotiation and condom use self-efficacy, and screening/management of psychosocial health problems. The intervention's effect on consistent condom use was estimated using difference-in-differences (DiD) approach. Mediation analysis assessed the extent to which intervention effects on the outcome were mediated by changes in psychosocial health problems and condom use self-efficacy. A process evaluation assessed implementation fidelity and intervention acceptability. Baseline consistent condom use was 43% in the intervention group and 46% in the standard-of-care group. Baseline survey findings demonstrated that a psychosocial syndemic of problematic alcohol use, internalised homonegativity and violence victimisation synergistically increased condomless anal intercourse. Using DiD, we estimated that the intervention increased consistent condom use with male partners by 16.4% (95% CI: 7.1, 25.7) and with female partners by 28.2% (95% CI: 11.9, 44.4), and decreased problematic alcohol use by 24.3% (95%CI: -33.4, -15.3), depression by 20.0% (95% CI: -27.6, -12.3) and internalised homonegativity by 34.7% (95% CI: -43.6%, -25.8%). The mediation analysis findings suggested that the intervention might have improved consistent condom use by decreasing internalised homonegativity and by increasing condom use self-efficacy. The process evaluation showed high levels of acceptability/satisfaction among participants and high levels of implementation fidelity. A syndemic theory-based intervention tailored for MSM in India is feasible, acceptable, and can reduce HIV transmission risk behaviour as well as problematic alcohol use, depression and internalised homonegativity.