Barriers and enablers of PrEP uptake among populations at risk for HIV in Indonesia: social, psychological, and structural perspectives.

Pre-exposure prophylaxis (PrEP) is effective for HIV prevention; however, its uptake remains uneven among key populations due to social norms, stigma, and structural barriers. In Indonesia, men who have sex with men, transgender individuals, female sex workers, and people who inject drugs navigate PrEP use within the context of the moral regulation of sexuality and unequal healthcare access. This study integrates the theory of planned behaviour (TPB) and the Health Belief Model (HBM), alongside stigma and multidimensional healthcare access, to examine the determinants of PrEP intentions and use. A cross-sectional survey of 315 participants was analysed using partial least squares structural equation modelling (PLS-SEM). The integrated model was quantitatively compared with four standalone frameworks (TPB, HBM, stigma, and healthcare access) and demonstrated a superior predictive performance. Subjective norms and perceived behavioural control were the strongest predictors of both intention and behaviour. Among the access dimensions, affordability was the only factor directly associated with intention and uptake. Perceived severity showed a negative association with PrEP outcomes, whereas stigma had indirect and nonsignificant effects. These findings highlight the importance of social influence, perceived capability, and economic access in shaping PrEP uptake.