O13.5 COMPARING MSM USING EVENT-DRIVEN PREP TO THOSE USING DAILY PREP – DATA FROM TWO EUROPEAN PREP DEMONSTRATION PROJECTS 1 V Jongen*, 2 T Reyniers, 1 Z Ypma, 1,3 M Schim van der Loeff, 1,4 U Davidovich, 1 H Zimmermann, 1 L Coyer, 1 M van den Elshout, 1,5 H de Vries, 2 K Wouters, 2 T Smekens, 2 B Vuylsteke, 1,3 M Prins, 2 M Laga, 1 E Hoornenborg. 1 Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, The Netherlands; 2 Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium; 3 Amsterdam UMC, University of Amsterdam, Internal Medicine, Amsterdam Infection and Immunity (AII), Amsterdam, The Netherlands; 4 Department of Social Psychology, University of Amsterdam, Amsterdam, The Netherlands; 5 Amsterdam UMC, University of Amsterdam, Department of Dermatology, Amsterdam Infection and Immunity (AII), location Academic Medical Centre, Amsterdam, The Netherlands 10.1136/sextrans-2021-sti.126 Background Daily and event-driven PrEP are both efficacious in preventing HIV infection. However, event-driven PrEP (edPrEP) is less well understood, in particular when provided as an alter- native to daily PrEP. We studied regimen preferences and switches, and sexually transmitted infection (STI) incidence. Methods We pooled data from the Dutch (AMPrEP) and the Belgian (Be-PrEP-ared) PrEP demonstration projects. In both projects, participants could choose between daily and event- driven PrEP (edPrEP) at 3-monthly study visits, when they were also screened for STIs including hepatitis C virus (HCV) infection. We assessed the proportion choosing each regimen, and the determinants of choosing edPrEP at baseline. Addi- tionally, we compared the incidence rates (IRs) of HCV, syphi- lis, and chlamydia or gonorrhoea between regimens using Poisson regression. Results The pooled dataset consisted of data of 571 men who have sex with men (n=374 AMPrEP; n=197 Be-PrEP-ared), of whom 148 (25.9%) chose edPrEP at baseline. Older partici- pants (adjusted odds ratio (aOR)=1.38 per 10 year increase, 95% confidence interval (CI)=1.15–1.64) and those unem- ployed (aOR=1.68, 95%CI=1.03–1.75) were more likely to choose edPrEP at baseline. Median follow up was 26 months [interquartile range 21–27]. 381 participants (68.3%) never switched between PrEP regimens, 96 (17.2%) switched once, and 81 (14.5%) more than once. After 28 months, 23.5% used edPrEP. IR of HCV and syphilis did not differ between regimens, but the IR of chlamydia/gonorrhoea was higher among daily users (adjusted incidence rate ratio=1.61, 95% CI=1.35–1.94). Conclusion A quarter of participants chose edPrEP at baseline and at 28 months this proportion was similar. The frequent switching suggests that participants adapt their PrEP regimen to their changing needs. Although the IR of HCV and syphilis were similar in both regimens, the lower incidence of chlamy- dia and gonorrhoea among edPrEP users may suggest that less frequent STI testing of this group could be considered. O13.6 DETERMINANTS OF PREP UPTAKE, INTENTION AND AWARENESS IN THE NETHERLANDS: A SOCIO-SPATIAL ANALYSIS 1 K Jonas, 1 H Wang*, 1 O Shobowale, 2 C den Daas, 3 E Op de Coul, 4 B Bakker, 5 A Radyowijati, 6 K Vermey, 6 A van Bijnen, 6 W Zuilhof. 1 Maastricht University, Maastricht, The Netherlands; 2 University of Aberdeen, Aberdeen, UK; 3 Epidemiology and Surveillance, Centre for Infectious Disease Control (RIVM), Utrecht, The Netherlands; 4 Rutgers, Utrecht, The Netherlands; 5 ResultsInHealth, Amsterdam, The Netherlands; 6 Soa Aids Nederland, Amsterdam, The Netherlands 10.1136/sextrans-2021-sti.127 Background Since its formal introduction in 2019, PrEP uptake in the Netherlands is growing, but remains at subopti- mal levels. Hence, the analysis of determinants is paramount. Given the initial focus of PrEP provision among men-who- have-sex-with-men (MSM) via a demonstration project, AmPrEP in Amsterdam, and pharmacies in the main urban areas (so called ‘Randstad’, entailing Amsterdam, Utrecht, Lei- den, The Hague and Rotterdam), investigating regional dis- crepancies is necessary. We seek to unravel regional differences jointly with known predictors of PrEP use, intention and awareness. Method This cross-sectional study included 3,232 HIV-negative Dutch MSM recruited via the EMIS survey in late 2017. Prev- alence and standardized prevalence ratio (SPR) of PrEP use, awareness and intention were measured on a regional level (Randstad vs. the rest of the country). Multi-level logistic modeling was conducted to identify the association of PrEP use with PrEP awareness and intention, sociodemographic, behavioral, psychological/cognitive determinants, and random effects from regional differences. Results MSM from Randstad used more PrEP (SPR=1.4 vs. 0.7) compared to the rest of the country, but there were minor differences for awareness and intention. The regional distinction was estimated to explain 4.6% of the PrEP use variance (adjusted ICC=0.046). Greater influence from inten- tion to use (OR=4.5, 95%CI 2.0–10.1) and knowledge of PrEP (OR=7.0, 95%CI 4.1–12.0), while limited influence from the awareness of PrEP was observed (OR=0.4, 95%CI 0.04–4.4). Lower education (OR=0.4, 95%CI 0.2–0.9) was negatively associated with PrEP use, however, no significant difference was found between middle and high education (OR=1.2, 95%CI 0.7- 2.0). Conclusion We showed that regional differences – MSM in non-urban regions – and with a low educational background account for lower PrEP use and intention. Based on these findings more fine-tuned PrEP access with a focus on non- urban regions can be implemented, and tailored campaigns increasing intention/use can be conducted among target populations. LGBTQ populations – MSM O14.1 BEHAVIOUR OR IDENTITY? DIFFERENCES IN HIV TESTING BY SEXUAL IDENTITY AMONG MSM IN HIGH- INCOME COUNTRIES: AN INDIVIDUAL PARTICIPANT DATA META-ANALYSIS 1 T Curtis*, 1 N Field, 2 L McDonagh, 3 A Schmidt, 4 M Holt, 5 B Bavinton, 6 P Saxton, 7 N Lachowsky, 1 C Mercer. 1 University College London, Institute for Global Health, London, UK; 2 University College London, NIHR Health Protection Research Unit in Blood Borne and Sexually Transmitted Infections, London, UK; 3 London School of Hygiene and Tropical Medicine, Sigma Research, London, UK; 4 UNSW Sydney, Centre for Social Research in Health, Sydney, Australia; 5 UNSW Sydney, Kirby Institute, Sydney, Australia; 6 University of Auckland, School of Population Health, Auckland, New Zealand; 7 University of Victoria, School of Public Health and Social Policy, Victoria, Canada 10.1136/sextrans-2021-sti.128 Background HIV testing guidelines recommend MSM test at least annually. However, heterosexual- and bisexual-identifying MSM (heterosexual-MSM; bisexual-MSM) may be less likely to test for HIV than gay-identifying MSM (gay-MSM). We hypothesised that differences in HIV testing may reflect Abstracts Sex Transm Infect 2021;97(Suppl 1):A1–A186 A47 on February 19, 2022 by guest. Protected by copyright. http://sti.bmj.com/ Sex Transm Infect: first published as 10.1136/sextrans-2021-sti.128 on 6 July 2021. Downloaded from