# Prevalence and factors associated with use of prophylaxis for HIV and sexually transmitted infections among sexual health service attendees in England: findings from a cross-sectional observational study

## TL;DR

This study examines how common it is for people in England to use HIV and STI prevention methods, finding that many gay and bisexual men use antibiotics to prevent STIs, with concerns about antibiotic resistance.

## Contribution

The study provides new insights into the use of STI PEP/PrEP among diverse sexual health service attendees in England, including non-GBMSM populations.

## Key findings

- 34% of GBMSM had heard of STI PEP/PrEP, and 11% reported using it, primarily doxycycline.
- Higher-risk sexual behavior was independently associated with STI PEP/PrEP use among GBMSM.
- Some MSW and women also use or are interested in antibiotic prophylaxis, suggesting broader potential benefits.

## Abstract

HIV pre-exposure prophylaxis (PrEP) demonstrates the value of biomedical interventions as part of combination prevention. Some gay, bisexual and other men who have sex with men (GBMSM) use antibiotics to prevent sexually transmitted infections (STIs), primarily as post-exposure prophylaxis (PEP). We aimed to understand variations in awareness and use of HIV PrEP and STI PEP/PrEP among people attending specialist sexual health services (SHSs) in England.

We collected data from 1732 SHS attendees aged >16 years in London and the East of England using an online questionnaire between April 2022 and December 2023, including awareness and use of HIV-PrEP and STI PEP/PrEP. We ran regression analyses: one to identify demographic factors associated with STI PEP/PrEP use among all SHS attendees, and a second to identify behavioural factors (controlling for sociodemographic factors) associated with antibiotic prophylaxis use among GBMSM.

The study recruited 1732 participants (50% GBMSM, 12% men who had reported sex with women only (MSW), 31% women). 74% had heard of HIV-PrEP but this varied by group (GBMSM: 98%, MSW: 39%, women: 49%). 34% of GBMSM had heard of STI PEP/PrEP and 11% reported using it (MSW: 15%/5%, women: 18%/4%). 61% of STI PEP/PrEP users reported taking doxycycline, mostly to prevent chlamydia, gonorrhoea and syphilis. 80% of all participants reported being somewhat/very likely to use event-based STI PEP/PrEP, with a higher proportion of GBMSM saying they would be likely to use STI PEP/PrEP in this way. In the behavioural regression model of GBMSM, use was independently associated with reporting higher-risk sexual behaviour (OR: 2.11, 95% CI 1.29 to 3.48).

We found that a sizeable minority of GBMSM already use STI PEP/PrEP, but some MSW and women also use or have an interest in antibiotic prophylaxis, suggesting potential benefits may exist for populations other than GBMSM. Communication should therefore emphasise appropriate antibiotic use and the risks of antibiotic resistance among all populations.