Predictors of linkage to prevention services after HIV post-exposure prophylaxis (PEP): A single-centre retrospective analysis, years 2019-2024

Background Post-exposure prophylaxis (PEP) remains underutilised and real-world data on its role within prevention pathways are limited. Given the challenging feasibility of randomised trials, observational studies are essential for describing the impact of PEP. Methods We conducted a retrospective observational study of PEP prescriptions following sexual exposure at the HIV Voluntary Counselling and Testing site of the National Institute for Infectious Diseases in Rome. Data included demographics, exposure, prior PEP/PrEP use, and follow-up through March 31, 2025. Mixed-effect logistic regression identified predictors of linkage to prevention services within three months Results A total of 1,366 PEP prescriptions were issued to 1,188 individuals from January 2019-December 2024. In 85.1% of the occasions, users were assigned male at birth and in 80.5% Italian-born. The most common exposures included receptive anal intercourse (35.3%), insertive anal intercourse (26.5%), insertive vaginal intercourse(11.2%), and sexual assault(8.5%). Prior PEP and PrEP were reported in 16.7% and 4.7% of the occasions, respectively. Follow-up was recommended in all; PrEP was advised in 46.1% occasions and initiated in 17.4%. Overall, users returned for follow-up in 46.5% of the cases. Multivariable analysis (n=871) showed that active PrEP recommendation and age≥35 years were positively associated with reattendance, while foreign birth and prior PEP were negatively associated. Nine persons (0.7%) were tested HIV positive; two at baseline and seven after PEP, suggesting missed opportunities for timely prevention. Conclusions This large-scale analysis from an Italian setting highlights the role of PEP as an entry point into HIV prevention pathways, while confirming gaps in linkage to ongoing preventive care. The Italian context, characterised by a high proportion of late HIV diagnoses and ongoing PrEP implementation, underscores the importance of strengthening prevention strategies. Structured follow-up and facilitated linkage to PrEP, when appropriate, may help maximise its preventive impact.