Preferences and willingness to use pre-exposure prophylaxis for HIV among men who have sex with men in mainland China and Hong Kong

Background: Pre-exposure prophylaxis (PrEP) uptake remains low in mainland China and Hong Kong. We examined preferences for different PrEP modalities among men who have sex with men (MSM) in mainland China and Hong Kong. Methods: We conducted a cross-sectional online survey from May to November 2022 in mainland China and Hong Kong. Eligible participants were aged ≥18 years, identified as MSM and self-reported HIV-negative, or unknown HIV status. Random forest models and SHapley Additive exPlanations analyses were used to identify key factors influencing preferences for and willingness to use six PrEP options: (1) daily oral, (2) on-demand oral, (3) monthly oral, (4) two-monthly injectable, (5) six-monthly injectable, and (6) implantable PrEP. Results: Among 2142 participants (mainland China: 1604; Hong Kong: 538), the mean age was 28.4 (±7.0) years in mainland China and 34.7 (±9.5) years in Hong Kong. Current PrEP use was similar between mainland China and Hong Kong (18.0% vs 17.8%, P = 0.93), with an additional 10.5% and 8.0% reporting past PrEP use (P = 0.11), respectively. A greater proportion of participants from mainland China preferred on-demand PrEP compared to those from Hong Kong (55.7% vs 48.1%, P < 0.01), whereas more participants from Hong Kong preferred monthly oral PrEP (53.2% vs 47.3%, P = 0.02). Willingness to use non-oral options was lower, with two-monthly injectable PrEP preferred by 21.1% (19.1-23.1%) in mainland China and 15.4% (12.3-18.5%) in Hong Kong (P < 0.01). Among Hong Kong participants, condom use frequency and migration status were important predictors of willingness to use both oral and injectable PrEP options. Current PrEP use status and PrEP attitudes were consistently important predictors. Additionally, individuals who preferred six-monthly injectable PrEP tended to dislike the two-monthly option. Conclusions: On-demand and monthly PrEP options remain the preferred choices, though the monthly oral option is neither proven nor available. However, the factors influencing these preferences vary, highlighting the need for tailored and targeted approaches to PrEP implementation.