The relationship between sexualised drug use and suboptimal antiretroviral therapy adherence in MSM living with HIV.

BACKGROUND: High adherence to antiretroviral therapy (ART) is crucial for maintaining viral load suppression in people living with HIV. This study aims to examine the association of sexualised drug use (SDU) with ART adherence in MSM. METHODS: In this cross-sectional study, adult MSM living with HIV and on ART were recruited from HIV specialist clinics in Hong Kong. They were invited to complete an online questionnaire on ART adherence measures, sex partner networking and SDU in the past 6 months. SDU pattern, intensity and recency were delineated by latent class analysis (LCA). The associations of suboptimal ART adherence measured by modified simplified medication adherence questionnaire with chemsex engagement, SDU, sex network centrality, and LCA classes were examined in logistic regression. RESULTS: In 2022-2024, 334 MSM who had started ART ≥ 2 years were included in analysis. A majority (93%) self-reported undetectable viral load but 23% had experienced viral load rebounds. Suboptimal ART adherence (46%) was associated with SDU and chemsex engagement, but not by SDU intensity in the affiliated LCA classes (infrequent drug use; intensive chemsex; former drug use). MSM with infrequent or intensive drug use and suboptimal ART adherence were more likely to be connected in the inferred networks. CONCLUSIONS: Regardless of drug use intensity, SDU and chemsex engagement were associated with suboptimal ART adherence, the latter correlated with HIV viral load rebound. Integrating interventions at HIV clinic visits aside, support service and its promotion could be disseminated through MSM's virtual networks.