OBJECTIVES:To evaluate the population-level impact of seven years of Scotland's HIV pre-exposure prophylaxis (PrEP) programme among gay, bisexual and other men who have sex with men (GBMSM). METHODS:National administrative data were used to estimate PrEP coverage and HIV incidence among 35 342 GBMSM attending specialist sexual health services between July 2015 and March 2024. Poisson regression was used to investigate the risk of HIV acquisition and its association with the extent of PrEP prescribing. RESULTS:PrEP coverage increased from 21% in the initial PrEP period (July 2017 to March 2020) to 45% in the latter period (April 2022 to March 2024). HIV incidence reduced from 4.46 per 1000 person-years in the pre-PrEP period (July 2015 to June 2017) to 1.66 in the initial PrEP period (aIRR 0.37, 95% CI 0.25-0.54) and remained stable thereafter. During the entire PrEP period, the risk of HIV acquisition was reduced among those 'currently prescribed' (involving 4 HIV acquisitions among 11 720 person-years) compared to those never prescribed (60 HIV acquisitions among 34 328 person-years) (aIRR 0.19, 95% CI 0.07-0.51). Compared to those currently prescribed PrEP, risk was greatest in those prescribed 12+ months ago (11 HIV acquisitions among 3824 person-years) (aIRR 8.13, 95% CI 2.58-25.64). CONCLUSIONS:HIV incidence was sustained at a low level as PrEP coverage broadened among GBMSM, but did not reduce further. Efforts to support persistence and re-engagement with PrEP are warranted in those at ongoing risk of HIV.

ObjectivesSuccess in HIV prevention interventions, including pre-exposure prophylaxis (PrEP), among gay, bisexual and other men-who-have-sex-with-men (GBMSM) has not been replicated across all communities. The 2025 BASHH/BHIVA UK PrEP Guidelines recognizes and addresses the significant barriers and constraints that existing guidance and service delivery models place on PrEP access and equity. This paper summarizes the key guideline recommendations and the rationale supporting them.MethodsThe guidelines were developed following the methodology described in the CEG Framework for Guideline development published on the BASHH website. The writing group of clinicians, academics and community advocates incorporated input from a formal public consultation process.ResultsThe 2025 guideline includes over 90 graded recommendations. A chapter on PrEP equity and an updated chapter on PrEP suitability and risk assessment, moving away from basing PrEP eligibility on the inclusion criteria used for clinical trials, are included. Injectable PrEP has demonstrated superiority to oral PrEP but presents challenges in delivery, so improving equity in access and uptake of existing oral PrEP options was a key priority. The guidelines simplify and clarify advice on dosing for oral PrEP and recommend new event-based dosing options for all PrEP users, including quick-start double-dose PrEP for everybody. New guidance on the use of PrEP after a potential exposure is also included.ConclusionsThe PrEP guidelines purposefully highlight equity, access and the urgent requirement to meet the needs of underserved communities as a priority. These are addressed through pragmatic and groundbreaking recommendations based on careful consideration of all available evidence.

IntroductionHIV pre-exposure prophylaxis (PrEP), in which people take HIV medication to prevent HIV acquisition, underpins global HIV transmission elimination strategies. Effective prevention needs people to adhere to PrEP and remain in care during periods of risk, but this is difficult to achieve. We undertook a process evaluation of Scotland's PrEP programme to explore barriers and facilitators to PrEP adherence and retention in care and to systematically develop evidence-based, theoretically-informed recommendations to address them.MethodsWe conducted semi-structured interviews and focus groups (09/2018-07/2019) with patients who identified as gay or bisexual men and were either using PrEP, had declined the offer of PrEP, had stopped PrEP, or had been assessed as ineligible for PrEP (n = 39 of whom n = 5 (13%) identified as trans, median age 31 years and interquartile range 14 years), healthcare professionals involved in PrEP provision (n = 54 including specialist sexual health doctors and nurses of various grades, PrEP prescribing general practitioners, health promotion officers, midwifes, and a PrEP clinical secretary), and clients (n = 9) and staff (n = 15) of non-governmental organisations with an HIV prevention remit across Scotland. We used thematic analysis to map key barriers and facilitators to priority areas that could enhance adherence and retention in care. We used implementation science analytic tools (Theoretical Domains Framework, Intervention Functions, Behaviour Change Technique Taxonomy, APEASE criteria) and expert opinion to systematically generate recommendations.ResultsBarriers included perceived complexity of on-demand dosing, tendency for users to stop PrEP before seeking professional support, troublesome side-effects, limited flexibility in the settings/timings/nature of review appointments, PrEP-related stigma and emerging stigmas around not using PrEP. Facilitators included flexible appointment scheduling, reminders, and processes to follow up non-attenders. Examples of the 25 recommendations include: emphasising benefits of PrEP reviews and providing appointments flexibly within individualised PrEP care; using clinic systems to remind/recall PrEP users; supporting PrEP conversations among sexual partners; clear on-demand dosing guidance; encouraging good PrEP citizenship; detailed discussion on managing side-effects and care/coping planning activities.ConclusionsPrEP adherence and retention in care is challenging, reducing the effectiveness of PrEP at individual and population levels. We identify and provide solutions to where and how collaborative interventions across public health, clinical, and community practice could address these challenges.

Background. HIV pre-exposure prophylaxis (PrEP) is key to HIV transmission elimination but implementation is challenging and under-researched. We undertook a process evaluation of the first 2 years of a national PrEP program to explore barriers and facilitators to implementation and to develop recommendations to improve implementation, focusing on PrEP uptake and initiation. Methods. Stage 1 involved semi-structured telephone interviews and focus groups (September 2018-July 2019) with geographically and demographically diverse patients seeking/using/declining/ stopping PrEP (n = 39), sexual healthcare professionals (n = 54), community-based organisation service users (n = 9) and staff (n = 15) across Scotland. We used deductive thematic analysis, to derive and then map key barriers and facilitators to priority areas that experts agreed would enhance uptake and initiation. In Stage 2, we used analytic tools from implementation science to systematically generate evidence-based, theoretically-informed recommendations to enhance uptake and initiation of PrEP. Results. Barriers and facilitators were multi-levelled and interdependent. Barriers included the rapid pace of implementation without additional resource, and a lack of familiarity with PrEP prescribing. Facilitators included opportunities for acquisition of practice-based knowledge and normalisation of initiation activities. We refined our 68 long-list' recommendations to 41 using expert input and the APEASE (Acceptability, Practicability, Effectiveness, Affordability, Side-effects, and Equity) criteria. Examples include: provision of PrEP in diverse settings to reach all in need; co-produced, culturally sensitive training resources for healthcare professionals, with focused content on non-daily dosing; meaningful collaborative working across all stakeholders. Conclusions. These evidence-based, theory informed recommendations provide a robust framework for optimising PrEP uptake and initiation in diverse settings to ensure PrEP reaches all who may benefit.

Background: Gay, bisexual and other men who have sex with men (GBMSM) are at far greater risk of experiencing poor mental health (MH) than wider society. This disparity was exacerbated by additional ‘unique to sexual minority status’ COVID-19 stressors.Objective: This sequential, mixed-methods study examined remote MH help-seeking among GBMSM in the U.K. and Ireland during the first COVID-19 lockdown.Methods and Results: Quantitative survey data (n = 1368), analysed with logistic regression, suggested GBMSM experiencing moderate-to-severe anxiety and those with a past MH diagnosis were most likely to seek MH support. Thematic analysis of qualitative interview (n = 18) data identified multiple barriers and enablers to GBMSM seeking remote MH help, with the help primarily sought from GBMSM-facing organisations and generic online resources. Finally, the behaviour change wheel was used to generate theoretically informed recommendations to promote MH help-seeking among GBMSM in Scotland.Implications: We discuss how applying these recommendations in the short, medium and long term will begin to address GBMSM’s MH needs, post COVID-19.

Objectives HIV Pre-Exposure Prophylaxis (PrEP) is a highly effective biomedical intervention for HIV prevention and is key to HIV transmission elimination. However, implementation is challenging. We identified barriers and facilitators to PrEP awareness and access during the roll out of Scotland’s national PrEP programme to develop recommendations for future provision. Design Multi-perspectival qualitative approach incorporating implementation science tools. Setting Sexual health services and sexual health/HIV community-based organisations (CBOs) in Scotland. Participants Semi-structured telephone interviews and focus groups with geographically and demographically diverse patients seeking/using/declining/stopping PrEP (n=39), sexual healthcare professionals (n= 54), CBO users (n=9) and staff (n=15). Analysis Using deductive thematic analysis we mapped barriers and facilitators to PrEP awareness and access. We then applied the Theoretical Domains Framework, Behaviour Change Wheel, and Behaviour Change Technique Taxonomy to analyse barriers and facilitators to generate targeted solutions. Finally, we applied APEASE criteria, expert opinion, and the socio-ecological model to synthesise and present multi-levelled and interdependent recommendations to enhance implementation. Results Barriers and facilitators were multifaceted, relating to the macrosocial (e.g., government, service ecology), the mesosocial (e.g., values and practices of organisations and dynamics and norms of communities) and the microsocial (peer influence). We derived 28 overarching recommendations including: incentivising organisations to share expertise, addressing future generations of PrEP users, expanding the reach of PrEP services, cascading effective service innovations, changing organisational cultures, instigating and managing novel outreach, establishing monitoring systems, supporting diverse PrEP users, providing training addressing awareness and access to professionals, and development of “PrEP champions” within a range of organisations. Conclusion Improving awareness and access to PrEP sustainably will require intervention across the whole system, changing policy and practice, organisations and their cultures, communities and their social practices, and individuals themselves. These evidence-based recommendations will prove useful in extending the reach of PrEP to all who could benefit. Strengths and limitations of this study ### Competing Interest Statement The investigators named have no financial interests that impact on their responsibilities towards the scientific value or potential publishing activities associated with the study. However, the team has other interests within the field including various roles relating to HIV and sexual health within Government (Steedman, Estcourt, Nandwani, Clutterbuck), policy generation (Steedman, Nandwani, Estcourt, Saunders, Young, Flowers, HIV Scotland), practice (Steedman, Estcourt, Nandwani, Clutterbuck, Saunders) and advocacy (Young, HIV Scotland). PF reports research grants from National Institute of Health Research UK, Chief Scientist Office of Scotland. RN reports research grants from National Institute of Health Research UK, Chief Scientist Office of Scotland and non-executive director membership of the Board of Public Health Scotland from April 2020. JF reports research grants from Chief Scientist Office of Scotland. CSE reports research grants from National Institute of Health Research UK, Chief Scientist Office of Scotland, Engineering and Physical Sciences Research Council, UK Clinical Research Collaboration, Health Protection Scotland, European Centres for Disease Control. JM, JS, IY, DC, NS, LM & JD report no competing interests. ### Funding Statement This study was funded by Chief Scientist Office grant number [HIPS/17/47]. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Glasgow Caledonian University Research Ethics Committee (REC) (HLS/NCH/17/037, HLS/NCH/17/038, HLS/NCH/17/044) and the South East of Scotland NHS REC (18/SS/0075, R&D GN18HS368) gave this study ethical approval. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes No data from this qualitative data set is publicly available. Supplementary file B provides an auditable account of anonymised data analysis.

Introduction HIV pre-exposure prophylaxis (PrEP) is a key component of HIV combination prevention. Effective prevention needs people to adhere to PrEP during periods of risk and remain in care. However, relevant models of care are under-researched. Using data from the first two years of Scotland’s PrEP programme, we explored barriers and facilitators to PrEP adherence and retention in care and systematically developed evidence-based, theoretically-informed recommendations to enhance future adherence and retention.Methods We conducted semi-structured interviews and focus groups (09/2018-07/2019) with geographically and demographically diverse patients who were either using/declined/stopped or had been assessed as ineligible for PrEP (n=39), healthcare professionals involved in PrEP provision (n= 54), non-governmental organisation service users (n=9) and staff (n=15) across Scotland. We used thematic analysis to map key barriers and facilitators to priority areas that could enhance adherence and retention in care. Next, we used analytic tools from implementation science (Theoretical Domains Framework, Intervention Functions, Behaviour Change Technique Taxonomy, APEASE criteria) and expert opinion to systematically generate recommendations to enhance future PrEP adherence and retention in care.Results Barriers and facilitators to adherence and retention in care were diverse and multi-layered. Barriers included perceived complexity of event-based dosing, the tendency for users to stop PrEP before seeking professional support, troublesome side-effects, limited flexibility in the settings, timings, and nature of appointments for follow up, enduring PrEP-related stigma and emerging stigmas around not using PrEP. Facilitators included flexible appointment scheduling, reminders, and processes to follow up non-attenders. We generated 25 wide-ranging but specific recommendations for key stakeholders, for example, emphasising the benefits of PrEP reviews and providing appointments flexibly within individualised PrEP care; using clinic systems to remind/recall PrEP users for review; supporting PrEP conversations among sexual partners; clear guidance on event-based dosing; encouraging/commitment to good PrEP citizenship; and detailed discussion on managing side-effects and care/coping planning activities.Conclusions PrEP adherence and retention in care is challenging for many people. Such challenges reduce the benefits of PrEP at individual and population levels. Our findings identify and provide solutions to where and how collaborative interventions across public health, clinical, and community practice could address these challenges.### Competing Interest StatementThe investigators named have no financial interests that impact on their responsibilities towards the scientific value or potential publishing activities associated with the study. However, the team has other interests within the field including various roles relating to HIV and sexual health within Government (Steedman, Estcourt, Nandwani, Clutterbuck), policy generation (Steedman, Nandwani, Estcourt, Saunders, Young, Flowers, HIV Scotland), practice (Steedman, Estcourt, Nandwani, Clutterbuck, Saunders) and advocacy (Young, HIV Scotland). PF reports research grants from National Institute of Health Research UK, Chief Scientist Office of Scotland. CSE, RN, JF, JM, JS, IY, DC, NS, LM & JD report no competing interests.### Funding StatementThis work was funded through Scottish Chief Scientist Office grant reference HIPS/17/47 Optimising services for people at highest risk of HIV: Developing best practice in delivering HIV pre-exposure prophylaxis (PrEP) through evaluation of early implementation across Scotland. The grant ran from June 2018 to October 2020. During this study, LMcD was funded by the UK Medical Research Council and Chief Scientist Office of the Scottish Government Health and Social Care Directorates at the MRC/CSO Social & Public Health Sciences Unit, University of Glasgow (MC\_UU\_12017/11, SPHSU11; MC\_UU\_00022/3, SPHSU18).### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The Glasgow Caledonian University Research Ethics Committee (HLS/NCH/17/037, HLS/NCH/17/038, HLS/NCH/17/044) and the South East Scotland National Health Service Research Ethics Committee (18/SS/0075, R&D GN18HS368) provided ethical approval.I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData that supports the findings and suggestions of this study are explained within the the supplementary material for this article, which presents elements of the original dataset.* APEASE : Affordability, Practicability, Effectiveness and cost-effectiveness, Acceptability, Side-effects and safety, Equity BBV : Blood borne viruses BCT : Behaviour Change Technique BCTT : Behaviour Change Technique Taxonomy BCW : Behaviour Change Wheel GBMSM : Gay, bisexual, and other men who have sex with men HIV : Human immunodeficiency virus PrEP : Pre-exposure prophylaxis STI : Sexually transmitted infection TDF : Theoretical Domains Framework

Background: During the acute COVID-19 pandemic HIV services in Scotland were rapidly redesigned to provide HIV care by telemedicine consultation, with only a proportion of face-to- face (FTF) care being reinstated from May 2020. To ensure service recovery was patient focused a working group representing multiple health boards across Scotland developed a patient survey to gain feedback on patients' experience of telemedicine consultations (telephone or video). Method: The questionnaire, based on previous sexual health patient questionnaires exploring views on telemedicine consultations, was adapted and piloted with 5 patients before being offered to patients having a telemedicine consultation for HIV care across Scotland from 24/08/20 to 13/01/21. Patients were invited to participate via telephone interview or a text-link to an online survey. Results were collated as simple proportions and common themes identified from free text responses. Results: 59 participants completed the survey in 7 Health Boards. The majority of respondents attend services in 1 health board (55%), identified as male (79%) and Scottish White (60%). They were mostly employed (71%). Almost all had a telephone consultation (97%). Participants were in their own home (88%), work (3%) or outside (7%) during their telemedicine consultation. Respondents were 'comfortable' talking with their clinician during telemedicine consultation (90%) which compared well with FTF consultation (85%), while 82% found telemedicine consultation 'acceptable'. Challenges attending FTF appointments were: getting time off work, access to parking and long journey time. Benefits of telemedicine consultation were: time saving, not having to travel and being able to attend from their location of choice. Respondents were concerned about telephone reception (50%) or internet access (35%), their ability to find a private space (38%) and confidence with video technology (30%). Respondents would like the option to choose the mode of future consultations, with a majority preferring a mixture of telephone and FTF (53%), telephone only (24%) or FTF only (19%). Conclusion: High levels of comfort and acceptability with telemedicine consultations were reported. Whilst the sample does not reflect our HIV community as a whole, the results support the continuation of telemedicine in HIV care in Scotland as part of a mixed model of care delivery.

Background The level of evidence for HIV transmission risk through condomless sex in serodifferent gay couples with the HIV-positive partner taking virally suppressive antiretroviral therapy (ART) is limited compared with the evidence available for transmission risk in heterosexual couples. The aim of the second phase of the PARTNER study (PARTNER2) was to provide precise estimates of transmission risk in gay serodifferent partnerships. Methods The PARTNER study was a prospective observational study done at 75 sites in 14 European countries. The first phase of the study (PARTNER1; Sept 15, 2010, to May 31, 2014) recruited and followed up both heterosexual and gay serodifferent couples (HIV-positive partner taking suppressive ART) who reported condomless sex, whereas the PARTNER2 extension (to April 30, 2018) recruited and followed up gay couples only. At study visits, data collection included sexual behaviour questionnaires, HIV testing (HIV-negative partner), and HIV-1 viral load testing (HIV-positive partner). If a seroconversion occurred in the HIV-negative partner, anonymised phylogenetic analysis was done to compare HIV-1 pol and env sequences in both partners to identify linked transmissions. Couple-years of follow-up were eligible for inclusion if condomless sex was reported, use of pre-exposure prophylaxis or post-exposure prophylaxis was not reported by the HIV-negative partner, and the HIV-positive partner was virally suppressed (plasma HIV-1 RNA < 200 copies per mL) at the most recent visit (within the past year). Incidence rate of HIV transmission was calculated as the number of phylogenetically linked HIV infections that occurred during eligible couple-years of follow-up divided by eligible couple-years of follow-up. Two-sided 95% CIs for the incidence rate of transmission were calculated using exact Poisson methods. Findings Between Sept 15, 2010, and July 31, 2017, 972 gay couples were enrolled, of which 782 provided 1593 eligible couple-years of follow-up with a median follow-up of 2.0 years (IQR 1.1-3.5). At baseline, median age for HIV-positive partners was 40 years (IQR 33-46) and couples reported condomless sex for a median of 1.0 years (IQR 0.4-2.9). During eligible couple-years of follow-up, couples reported condomless anal sex a total of 76 088 times. 288 (37%) of 777 HIV-negative men reported condomless sex with other partners. 15 new HIV infections occurred during eligible couple-years of follow-up, but none were phylogenetically linked within-couple transmissions, resulting in an HIV transmission rate of zero (upper 95% CI 0.23 per 100 couple-years of follow-up). Interpretation Our results provide a similar level of evidence on viral suppression and HIV transmission risk for gay men to that previously generated for heterosexual couples and suggest that the risk of HIV transmission in gay couples through condomless sex when HIV viral load is suppressed is effectively zero. Our findings support the message of the U=U (undetectable equals untransmittable) campaign, and the benefits of early testing and treatment for HIV. Copyright (C) 2019 The Author(s). Published by Elsevier Ltd.

The guidelines are aimed at clinical professionals directly involved in, and responsible for, HIV prevention, and at community advocates and organisations responsible for supporting HIV prevention strategies in those at risk of HIV acquisition. A detailed review of the evidence base is included in Section 4. Sections 5–7 are intended to offer practical guidance in risk assessment, starting PrEP, ongoing management while on PrEP and stopping PrEP. We recognise the importance of these guidelines being inclusive and relevant to all, regardless of sexuality or gender identity or expression. For the sake of brevity in the main text of the guidelines, phrases such as "men who have sex with men" refer to cis-gender or non-binary or gender-queer men who have sex with men and "heterosexual men and women" refer to cis-gender or non-binary or gender-queer men and women who have heterosexual sex. Where sections are specifically relevant to trans people, we identify this using the terms trans people, trans men or trans women. The multidisciplinary guideline writing group developed the guidelines based on the process outlined in the BHIVA Guidelines Development Manual 1. All members of the group underwent GRADE training. We undertook a comprehensive literature review on PrEP and HIV prevention using the PICO question shown below. The recommendations are the result of a series of face-to-face and virtual meetings of the writing group and a meeting of community activists and organisations who commented on a draft of the guidelines in May 2017. The writing group also reviewed and incorporated input from the public consultation process. The literature review search was from January 2004 to May 2016. Medline, Embase and Cochrane databases were searched. Only papers in English were included and animal studies were excluded. In addition, although the formal literature review was not repeated, subsequent evidence published between May 2016 and July 2017 that the writing group felt was relevant has been included. A Grade 1 recommendation is a strong recommendation to do (or not do) something, where benefits clearly outweigh risks (or vice versa) for most, if not all, patients. Most clinicians and patients would want to follow a strong recommendation unless there is a clear rationale for an alternative approach. A strong recommendation usually starts with the standard wording "We recommend". A Grade 2 recommendation is a weaker or conditional recommendation, where the risks and benefits are more closely balanced or are more uncertain. Alternative approaches or strategies may be reasonable depending on the individual patient's circumstances, preferences and values. A weaker or conditional recommendation usually starts with the standard wording "We suggest". The strength of a recommendation is determined not only by the quality of evidence for defined outcomes, but also the balance between desirable and undesirable effects of a treatment or intervention, differences in values and preferences, and where appropriate, resource use. Each recommendation concerns a defined target population and is actionable. In addition to graded recommendations, the writing group has also included good practice points (GPPs). GPPs are recommendations based on the clinical judgement and experience of the working group and feedback from community and public consultation. GPPs emphasise an area of important clinical practice for which there is not, nor is there likely to be, any significant research evidence. They address an aspect of treatment and care that is regarded as such sound clinical practice that healthcare professionals are unlikely to question it, and where the alternative recommendation is deemed unacceptable. It must be emphasised that GPPs are not an alternative to evidence-based recommendations. The guideline writing group included representation from Terrence Higgins Trust and NAZ. In order to widen the stakeholder involvement, a meeting of community activists and organisations was held in May 2017, when feedback was sought on the content of the draft guidelines and recommendations prior to wider public consultation. We acknowledge the following for their helpful contributions: Yusef Azad (NAT), Takudzwa Mukiwa (THT), Will Nutland (Prepster), Greg Owen (I Want PrEP Now), Michelle Ross (CliniQ), Sophie Strachan (Sophia Forum), Marc Thompson (Prepster/Black Out UK) and George Valiotis (HIV Scotland). The guideline writing group recognises that although the PrEP trials used tenofovir disoproxil fumarate (TDF), increasingly other salts of tenofovir disoproxil (including maleate, succinate and phosphate) will be used in generic formulations. We have therefore used the acronym TDF-FTC where Truvada was used in a trial and TD-FTC to denote all other (generic) forms of tenofovir disoproxil and emtricitabine. The iPrEx study 1 was a Phase 3, randomised, double blind, placebo-controlled, multi-centre trial conducted among 2499 MSM and trans male-to-female adults (n = 339) in Peru, Ecuador, Brazil, Thailand, South Africa and the United States. Participants were randomly assigned to either a daily dose of TDF-FTC (1251 participants) or placebo (1248 participants). Primary outcome was HIV infection with a total of 3324 person-years of follow-up. Over the course of the study, 100 participants became infected with HIV; 36 in the TDF-FTC group and 64 in the placebo group, representing a 44% (95% confidence interval [CI] 15–63) reduction in HIV incidence using a modified intention-to-treat (ITT) analysis, excluding those confirmed HIV positive at randomisation. Efficacy was higher in the per-protocol analysis; at visits where adherence was >50% by self-report and pill count/dispensing, efficacy was 50% (95% CI 18–70). The PROUD study was a Phase 3, randomised, open-label, multi-centre trial conducted in 544 MSM at 13 sexual health clinics in England 2. Participants were randomly assigned to a daily dose of TDF-FTC immediately (275 participants), or after a deferral period of 12 months (269 participants). Primary outcomes were time to accrual of 500 participants and retention at 12 and 24 months; HIV infection was a secondary outcome. At interim review, the DSMB recommended that all study participants should be offered study drug. A total of 23 participants became infected with HIV over the course of the study: three in the daily TDF-FTC group and 20 in the deferred (no-PrEP) group, representing a rate difference in HIV infection of 7.8 per 100 person-years (90% CI 4.3–11.3) The relative risk reduction was 86% (90% CI 64–96%) and the number needed to treat over 1 year to prevent one HIV infection was 13 (90% CI 9–23). The IPERGAY study was a Phase 3 double-blind, randomised, multi-centre trial conducted among 414 MSM in France and Canada 3. Participants were randomly assigned to either receiving an on-demand regimen of TDF-FTC (206 participants) or placebo (206 participants). The on-demand regimen involved taking a double dose of TDF-FTC 2–24 h before sex, and a daily dose during periods of sexual risk and for 48 h (two doses) after ceasing sexual risk. Participants were followed up every 8 weeks for HIV testing and risk-reduction advice, and every 6 months for sexually transmitted infection (STI) testing for a total of 431 person-years of follow-up. Primary endpoint was HIV infection. At interim review, the placebo group was discontinued and all study participants were offered study drug. Over the course of the study, 16 people became infected with HIV: two in the TDF-FTC group and 14 in the placebo group, representing a relative risk reduction of 86% (95% CI 40–98%) in the ITT analysis. One Phase 2 safety trial, the CDC MSM Safety Trial 4, compared tenofovir (TDF) to placebo in a randomised, double-blind, placebo-controlled, wait-listed design among 400 HIV-negative MSM. Participants were randomly assigned in a 1:1:1:1 design to receive TDF or placebo immediately or after 9 months. Main endpoints were safety and behavioural outcomes. There were no infections among those taking active drug. Seven participants seroconverted: four in the placebo arm and three among delayed-arm participants who were not on the study drug. An eighth participant was HIV positive at enrolment. Two further smaller studies include a pilot feasibility and acceptability study, Project PrEPare, which recruited 58 young MSM aged 18–22 years in the United States. Participants were randomly allocated to receive a behavioural intervention alone, the behavioural intervention and PrEP (TDF-FTC) or the behavioural intervention and placebo. There were no seroconversions among the 58 participants 5. The IAVI Kenya Study was a small safety and adherence study conducted among Kenyan MSM and female commercial sex workers (CSWs). Sixty-seven MSM and five female CSWs were randomly assigned to daily TDF-FTC or placebo, or intermittent (Monday, Friday and within 2 h after sex) TDF-FTC or placebo in a 2:1:2:1 ratio. There was one seroconversion in the placebo arm 6. The iPrEx Open-label Extension (iPrEx-OLE) 7 enrolled 1603 HIV-negative men and 339 (14%) trans women who have sex with men who were previously part of PrEP studies (iPrEx, ATN082/Project PrEPare and CDC MSM Safety Trial). Participants were offered daily TDF-FTC and were followed up for 72 weeks after enrolment. Uptake was high at 76%, and this was higher among those reporting condomless receptive anal intercourse and those who were herpes simplex-2 virus (HSV-2) seropositive, suggesting use during periods of risk. HIV incidence was 1.8 infections per 100 person-years, compared with 2.6 infections per 100 person-years in those who concurrently did not choose PrEP (hazard ratio [HR] 0.51, 95% CI 0.26–1.01, adjusted for sexual behaviours) 7. Examination of drug levels by dried blood spot testing was extrapolated to pill taking and compared to HIV incidence each quarter. No seroconversions were seen when drug levels were compatible with taking four or more pills per week. The IPERGAY Open-label Extension (IPERGAY-OLE) enrolled 362 individuals to take on-demand TDF-FTC and followed them for a median of 11.7 months, of whom 299 (83%) completed follow-up with a single HIV infection (0.19 per 100 person-years, 95% CI 0.01–1.08) 8. A community-based clinic in San Francisco screened 1249 MSM (and three trans men) and offered PrEP with TDF-FTC with 95.5% uptake. Condomless sex was reported by 93% at enrolment. After a maximum of 16 months' follow-up there were no new HIV infections in the men enrolled in the programme 9. At the time of writing there have been three case reports of HIV transmissions in MSM taking PrEP despite apparent confirmed adherence. Two individuals were infected with resistant virus and, in one case, transmission occurred with wild-type virus sensitive to both tenofovir and emtricitabine 10. Efficacy of PrEP is highly dependent on adherence, with a meta-analysis of PrEP studies 12 demonstrating that adherence is a significant moderator of PrEP effectiveness. The higher the levels of adherence to oral PrEP in the study population, as measured by detectable drug, the greater the efficacy. In the iPrEX study, adherence was monitored using pill count and self-reported adherence. Pharmacokinetic plasma and intracellular drug-level sampling was conducted in a pre-specified subgroup analysis where subjects with HIV infection were matched with two controls selected from seronegative subjects. In those who had detectable drug levels of TDF-FTC, the reduction in HIV incidence was 92% (95% CI 40–99%) compared to those who had no drug detected 1, suggesting that a high level of adherence is associated with a high level of efficacy. In the PROUD study, adherence was monitored using prescription data, self-reported adherence and drug levels in a convenience sample of study participants. Overall, sufficient study drug was prescribed for 88% of the total follow-up time and tenofovir was detected in all samples taken from 52 participants who reported taking study drug within the preceding 3 days 2. In the IPERGAY study, adherence was monitored using pill counts, self-reported adherence and drug levels in a subset of 113 participants. Of participants in the active treatment group who had drug levels measured, protective drug levels of tenofovir were detected in 86%. However, computer-assisted interview (CASI) data collected in 319 participants in the randomised phase suggested that only 43% of people took study drug correctly during last sexual intercourse, 29% took a suboptimal dose and 28% did not take the study drug at all 3. In the open-label phase, adherence in 362 men completing 1617 CASI returns reported 50% of men taking study drug correctly during last sexual encounter, 24% taking a suboptimal dose and 26% taking no study drug at all 8. Comparison of adherence to different regimens of TDF-FTC PrEP has been investigated in MSM in the HPTN 067 (ADAPT) study. The study recruited MSM and trans women in Harlem (New York, USA) and Thailand and heterosexual women in South Africa. Following a 4-week phase of daily dosing, participants were randomly assigned 1:1:1 to one of three regimens: daily dosing ("daily") or one tablet twice a week and one tablet post sex ("time driven") or one tablet 24–48 h before sex and one tablet within 2 h after sex ("event-based"). Results from 178 Thai MSM showed that coverage (defined as taking more than one pill in the 4 days before sex and more than one pill in the 24 h afterwards) was significantly higher in the daily (85% of events covered) and time-driven (84%) arms than in the event-driven arm (74%). Two seroconversions occurred in the 4 week pre-randomisation phase 13. In 179 MSM in Harlem, figures were 66%, 47% and 52%, respectively, with one seroconversion in the pre-randomisation phase and one in the randomised phase 14. Adherence was higher in the daily-dose arms: in Thailand, 85% of daily doses, 79% of twice-weekly doses, and 65% of event-driven doses were taken as prescribed. In Harlem, the respective figures were 65%, 46% and 41%. Although these represent two diverse populations of MSM in different settings, the study demonstrated similar coverage of sex acts for daily and non-daily regimens with both groups demonstrating lower adherence and coverage rates for the event-driven approach. Higher coverage of events in the Thai MSM was associated with older age and higher level of education. Use of stimulant drugs and higher sexual frequency was associated with lower coverage 15. To date, studies of TDF-FTC PrEP suggest short-term safety. A meta-analysis of PrEP studies 12 demonstrated no difference in the proportions of adverse events comparing PrEP to placebo across 10 placebo-controlled RCTs (odds ratio [OR] 1.01, 95% CI 0.99–1.03, P = 0.27) with no differences seen in subgroup analysis that included mode of acquisition, adherence, sex, drug regimen, dosing or age. No differences were seen in grade 3 or 4 adverse events comparing PrEP and placebo groups across 11 placebo-controlled RCTs (risk ratio [RR] 1.02, 95% CI 0.92–1.13, P = 0.76). Results were not presented by subgroup. In the iPrEx study, there was no difference in reported adverse events between the two study arms: 867/1251 (67%) of participants in the TDF-FTC arm reported any adverse event, compared to 877/1248 (70%) in the control arm. Both arms reported similar rates of grade 3 and 4 adverse events: 151/1251 (12%) of TDF-FTC participants compared to 164/1248 (13%) of control-arm participants 1. There was no difference in permanent or temporary discontinuation of study drug between the two arms: 25/1251 (2%) permanent discontinuations in the intervention arm compared to 27/1248 (2%) in the placebo arm and a total of 79/1251 (6%) permanent or temporary discontinuations in the intervention arm compared to 72/1248 (6%) in the placebo arm. However, nausea was more common among those taking TDF-FTC compared to placebo in the first month (95% vs. 5%). Depression-related adverse events were the most common severe or life-threatening adverse events reported in iPrEx, but were not associated with being randomly assigned to TDF-FTC (OR 0.66, 95% CI 0.35–1.25) 16. In the PROUD study, 21/275 participants (8%) interrupted or missed study drug doses because of adverse events, the commonest of which were headache and nausea 2. In IPERGAY, drug-related gastrointestinal adverse events were reported more commonly in the TDF-FTC group compared to the placebo group (14% vs. 5%, P = 0.002), but there was no difference in the frequency of grade 3 or 4 adverse events 3. PrEP trials have shown modest, but statistically significant declines in renal function with administration of daily TDF-FTC, but the incidence of serious renal events was very low and mostly reversible. In PROUD, three participants interrupted drug due to elevated creatinine concentrations (two were classed as mild elevation, defined as 1.1–1.3 times the upper limit of normal [ULN], and one as moderate, 1.4–1.8 ULN), although the most likely explanation in one man was recreational drug use and the other two men were older with comorbidities 2. In the IPERGAY study, 18% of active drug participants experienced elevated creatinine levels compared to 10% of placebo group (P = 0.03). All, but one were mild and transient and none led to discontinuation of study drug 3. In the iPrEx study, use of TDF-FTC was associated with a mild non-progressive decrease in estimated creatinine clearance (CrCl) of 2.4% from baseline, which was reversible 14. Creatinine elevations of >1.1 ULN were similar between active and placebo arms, occurring in 32 (2.6%) in the active arm and 24 (2.2%) in the placebo arm (RR 1.35, 95% CI 0.80–2.3). Most excess creatinine elevations in the active arm of the study (median follow-up 72 weeks) occurred at 12–24 weeks and all occurred at <48 weeks. Proteinuria by dipstick was detected regularly (613/5081 [12%] dipsticks performed), but there was no between-group difference in the proportion of participants ever positive for proteinuria (20% placebo vs. 21% TDF-FTC; P = 0.62). In addition, the positive predictive value of proteinuria in predicting a confirmed creatinine elevation was poor at 0.7% 14. In iPrEx-OLE the probability of CrCl falling to ≤60 mL/min at least once over the first year on PrEP was low, but was more likely when participants started PrEP at older ages (>40 years) or with a starting CrCl ≤90 mL/min 15. For participants under 40 years of age, the mean decline in CrCl over the duration of the study (median 72 weeks) was modest (−2.6%) and no patients experienced a CrCl drop to ≤60 mL/min, even in those with full adherence to daily dosing, indicating that annual monitoring of renal function in this group should be sufficient. However, being aged >40 years or with a lower baseline creatinine clearance (≤90 mL/min) at initiation of PrEP were independently associated with a risk of CrCl falling to ≤60 mL/min, especially with daily dosing. This suggests that more frequent renal monitoring on PrEP may be required in older PrEP users (>40 years) and in those with marginal renal function at baseline, even if there are no other concomitant risk factors for renal disease. In an iPrEx sub-study of 500 participants who underwent 6-monthly DEXA scans to assess bone mineral density (BMD), a small net decrease in BMD of 0.7–1% was seen among those randomly assigned to TDF-FTC (n = 247) compared to placebo (n = 256) after 24 weeks in both spine and total hip measures 17. There are no long-term data on bone health for people on TDF-FTC PrEP. In the CDC MSM study, in multivariate analysis, back pain was associated with use of TDF and also a small decrease in BMD among a subset of 184 men in the San Francisco site. However, TDF use was not associated with bone fractures 18. In the iPrEx trial, FTC-related drug resistance developed in two participants who had unrecognised acute HIV infection at baseline 19. These individuals had a negative antibody test before starting PrEP, but later tested positive. In the PROUD study, two of the three participants with a positive HIV test at enrolment or the 4-week visit had FTC-related drug resistance; no resistance was detected in participants who acquired HIV post-randomisation 2. In IPERGAY, none of the incident HIV infections post-randomisation demonstrated resistance mutations to study drug 3. In a meta-analysis, Fonner et al. reviewed results from six trials that reported cases of FTC or TDF drug resistance using standardised genotypic laboratory assays 12. Although the only study of MSM included in this analysis was iPrEx, the risk factors associated with development of drug resistance will be similar in MSM and people who have heterosexual sex. The risk of developing an FTC-related mutation among those acutely infected with HIV at enrolment was significantly higher in the group randomly allocated to receive TDF-FTC compared to placebo (risk ratio 3.72, 95% CI 1.23–11.23, P = 0.02). The risk of a TDF-related mutation was not statistically different between PrEP and placebo, regardless of PrEP regimen, among those acutely infected at enrolment. Additionally, six (2%) TDF- or FTC-resistant infections occurred among 544 post-randomisation HIV infections: five in PrEP groups and one in a placebo group. Numbers were too small to calculate a pooled relative risk. Risk behaviour has been measured using outcomes including STI diagnoses, condom use and sexual partner numbers. The most clinically relevant outcome is STI diagnoses, not least because the other two indicators are self-reported and, as such, subject to reporting bias. In the placebo-controlled trials, one purpose of the placebo is to control for behaviour, and it is not possible to comment on the impact of PrEP on behaviour, as participants do not know if they are on active drug. However, it is possible to evaluate the impact of the risk-reduction support provided to all participants, and there were demonstrable benefits in iPrEx, the CDC MSM Safety Trial, but not the IAVI Kenya study. In the iPrEx study, both PrEP and placebo groups reported increased condom use over the course of the study and reported condom use did not differ between the arms (P = 0.36) 1. The number of reported receptive sexual intercourse partners in both arms also declined over the course of the study, with no significant difference in the number of partners reported in each group at each time point (P = 0.97) 1. The reduction in risk behaviours may reflect the fact that the majority of iPrEx participants came from populations with little access to risk-reduction support. In IPERGAY, there were no significant differences between TDF-FTC and placebo groups in the proportion of condomless receptive anal sex (P = 0.40) and incident STIs (P = 0.10). There was a slight but significant decrease in the number of sexual partners in the previous 2 months in the placebo group compared to the TDF-FTC group (7.5 vs. 8, P = 0.001) 3, 20. In the CDC MSM Safety Trial (also placebo-controlled), mean number of sexual partners in the previous 3 months and the proportion reporting condomless anal sex declined over 24 months of follow-up. The IAVI Kenya study, which included MSM, was the only trial to report an increase in study partners from baseline to follow-up, but partners may have been underreported at baseline 6. In the open-label PROUD study, in which participants knew they were taking PrEP and that it was at least partially effective, there was no difference between the immediate and deferred (no-PrEP) groups in the total number of sexual partners (P = 0.57) in the 3 months prior to the 1-year questionnaire, but a greater proportion of the immediate group reported receptive anal sex without a condom with 10 or more partners compared to the deferred group (21% vs. 12%, P = 0.03). There was no difference in the frequency of bacterial STIs during the randomised phase (P = 0.74) 2. In the iPrEx-OLE study, both groups reported decreases in reported condomless receptive anal intercourse from 34% (377/1115) to 25% (232/926 P = 0.006) among those accepting PrEP and from 27% (101/369) to 20% (61/304; P = 0.03) in the group who declined PrEP. Conversely, in IPERGAY-OLE there was a much higher baseline rate and a significant increase in reported condomless sex at last receptive anal intercourse from 77% at baseline to 86% at 18 months (P = 0.003 for trend) 8. Examination of three different trajectories of condom use (low, medium and high) and four of PrEP use over time in IPERGAY-OLE shows that in the majority of men, declines in condom use were compensated by increased on-demand PrEP use, but in a minority of men this was not the case. Compensation by using on-demand PrEP was lower in younger men for all three condom trajectories 21. In a large observational cohort study of MSM PrEP in a community-based clinic in San Francisco, self-reported condom use for different sub-cohorts of men taking PrEP for periods of 1–16 months was unchanged in 38–61%, increased in 5–12% and reduced in 16–48% 9. Both the PROUD and IPERGAY studies documented high levels of bacterial STIs in MSM throughout the course of follow-up. Within IPERGAY, participants were screened at enrolment and every 6 months during follow-up for chlamydia and gonorrhoea (with triple site nucleic acid amplification tests) and syphilis 10. Of participants receiving TDF-FTC, 41% acquired a new STI during follow-up, compared to 33% in the placebo arm; most STIs were rectal and 10% acquired a new syphilis infection 3. Similar results were observed within the PROUD study where 3- to 6-monthly STI screening was offered and the proportions with a bacterial STI were 50% and 57% of men diagnosed with an STI, respectively, in the deferred and immediate treatment arms of the study (P = 0.74). Similarly to IPERGAY, 10% of individuals in PROUD acquired a new syphilis infection 2. In iPrEx OLE the incidence of syphilis was similar in both groups, although numerically higher among PrEP users (7.2/100 person-years compared to 5.4/100 person-years in non-PrEP users, HR 1.35, 95% CI 0.83–2.19). In IPERGAY, incidence rate of first STI was 35.2 per 100 person-years in the double-blind phase, and 40.6 per 100 person-years in the open-label phase 3. Incident hepatitis C has also been reported in clinical trials and PrEP access projects. In Amsterdam, HIV-negative MSM who enrolled in the Amsterdam PrEP demonstration project had considerably higher hepatitis C virus (HCV) prevalence at 4.8% than HIV-negative MSM in the general Amsterdam STI clinic survey at 0.3–1.2% 22. Genetic analyses suggested that circulating HCV strains in HIV-negative men starting PrEP were similar to those in local HIV/HCV co-infected MSM. In the PROUD study, 5/160 (3.1%) participants who had tested on one or more occasions for HCV had incident HCV infection (3.1%). There were three incident HCV infections in the immediate arm and two in the deferred arm 2. In IPERGAY, overall, there were five incident HCV infections 3 suggesting that HIV-negative men on PrEP are at risk of HCV infection and should undergo regular testing for HCV while on PrEP. Two RCTs have demonstrated the efficacy of daily oral PrEP in preventing HIV acquisition among heterosexual individuals. One Phase 3 RCT, Partners PrEP 1, assessed the efficacy of daily oral TDF vs. TDF-FTC vs. placebo in serodifferent heterosexual couples in East Africa and one Phase 3 RCT, TDF-2 2, evaluated TDF-FTC vs. placebo in sexually active heterosexual adults at high risk of HIV acquisition in Botswana. No studies have evaluated the efficacy of an on-demand PrEP regimen in heterosexuals and to date there have been no RCTs undertaken in heterosexual men and women in high-income countries. Although there is no reason to think the biological efficacy would be different, given the lack of RCTs in heterosexuals in high-income countries, it remains difficult to generalise the finding of high PrEP efficacy from these two trials in sub-Saharan Africa (SSA) to the UK because HIV incidence is much lower, and no well-defined group of heterosexuals with high HIV incidence can be identified in national surveillance data. Furthermore, there are likely to be differences in cultural beliefs and sociodemographic circumstances that influence adherence and efficacy and further complicate any extrapolation of the data. Two RCTs (FEM-PrEP 3 and VOICE 4), both in heterosexual women in SSA, reported low efficacy rates of daily oral PrEP. In both cases, the studies were well conducted and the null results, and inconsistency of the results when compared to TDF-2 and Partners PrEP, are primarily attributed to low adherence (measured using drug levels) to the study drug in the intervention arm. Partners PREP was a double-blind, placebo-controlled Phase 3 RCT following 4747 heterosexual couples, comparing single and dual agent PrEP (TDF vs. TDF-FTC) with placebo conducted from 2008 to 2010 1. Participants were sexually active serodifferent heterosexual couples in Uganda and Kenya. HIV-negative participants were aged between 18 and 65 years, sexually active with an HIV-positive partner (≥6 episodes of vaginal intercourse with HIV-positive partner in the past 3 months) with no chronic HBV infection. HIV-negative women who were breastfeeding, pregnant or planning to become pregnant were excluded from the study. The study also excluded HIV-negative participants with glycosuria or proteinuria, ongoing therapy with certain drugs, and a history of pathological bone fractures not related to trauma. HIV-positive sexual partners were >18 years old, sexually active, with CD4 cell counts ≥250 cells/mL, no history of AIDS-defining illnesses and not using antiretrovirals (ARVs). The HIV incidence in the control arm was 1.99 per 100 person-years. Overall, the study found the efficacy of PrEP using TDF alone was 67% (95

The British Association for Sexual Health and HIV (BASHH) United Kingdom national guideline on the sexual health care of men who have sex with men (MSM) was published in electronic format in this journal in 2018. In common with other BASHH guidelines, the document fulfils the dual role of scrutinising and evaluating the available evidence according to the accredited Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, as well as the often more challenging job of codifying and summarising expert opinion in areas where the evidence base is incomplete or lacking. In addition to the learning gained from developing the recommendations included in the final document, further benefit was derived from the process through a number of learning and development actions for the writing group and through this the MSM special interest group and the wider sexual health community.

This guideline is intended for use in UK Genitourinary medicine clinics and sexual health services but is likely to be of relevance in all sexual health settings, including general practice and Contraception and Sexual Health (CASH) services, where men who have sex with men (MSM) seek sexual health care or where addressing the sexual health needs of MSM may have public health benefits. For the purposes of this document, MSM includes all gay, bisexual and all other males who have sex with other males and both cis and trans men. This document does not provide guidance on the treatment of particular conditions where this is covered in other British Association for Sexual Health and HIV (BASHH) Guidelines but outlines best practice in multiple aspects of the sexual health care of MSM. Where prevention of sexually transmitted infections including HIV can be addressed as an integral part of clinical care, this is consistent with the concept of combination prevention and is included. The document is designed primarily to provide guidance on the direct clinical care of MSM but also makes reference to the design and delivery of services with the aim of supporting clinicians and commissioners in providing effective services. Methodology This document was produced in accordance with the guidance set out in the BASHH CEG's document 'Framework for guideline development and assessment' published in 2010 at http://www.bashh.org/guidelines and with reference to the Agree II instrument. Following the production of the updated framework in April 2015, the GRADE system for assessing evidence was adopted and the draft recommendations were regraded. Search strategy (see also Appendix 1) Ovid Medline 1946 to December 2014, Medline daily update, Embase 1974 to December 2014, Pubmed NeLH Guidelines Database, Cochrane library from 2000 to December 2014. Search language English only. The search for Section 3 was conducted on PubMed to December 2014. Priority was given to peer-reviewed papers published in scientific journals, although for many issues evidence includes conference abstracts listed on the Embase database. In addition, for 'Identification of problematic recreational drug and alcohol use' section and 'Sexual problems and dysfunctions in MSM' section, searches included PsycINFO. Methods Article titles and abstracts were reviewed and if relevant the full text article was obtained. Priority was given to randomised controlled trial and systematic review evidence, and recommendations made and graded on the basis of best available evidence. Piloting and feedback The first draft of the guideline was circulated to the writing group and to a small group of relevant experts, third sector partners and patient representatives who were invited to comment on the whole document and specifically on particular sections. The revised draft was reviewed by the CEG and then reviewed by the BASHH patient/public panel and posted on the BASHH website for public consultation. The final draft was piloted before publication. Guideline update The guidelines will be reviewed and revised in five years' time, 2022.

In this issue, Weatherburn et al and Pakianathan et al provide a combination of practical and empirical insights into ‘chemsex’. This is particularly relevant to clinicians working with gay and bisexual men who have sex with men (GBMSM). Here we outline further issues for practitioners working with GBMSM who engage in chemsex. Chemsex describes GBMSM's use of new recreational drugs (primarily mephedrone, crystal methamphetamine and γ-hydroxybutyric/γ-butyrolactone) to enable, enhance and prolong sexual interactions. Unlike alcohol and most other recreational substances, chemsex drugs provide men with the ability to improve their sexual performance and experiences, by increasing arousal, stamina and pleasure.1 Arising in tandem, the proliferation of geospatial sociosexual networking apps provide access to local sexual activities and drug procurement on demand.2 Together, these developments allow multiple and group sexual hook-ups to be arranged, outside the spatiotemporal constraints of the commercial (gay) scene, which usually last many hours or even several days. As well allowing increased partner numbers and turnover, chemsex users operate within a distinct cultural ‘bubble’, where risky sex and recreational drug use are normalised and advance negotiation of drug supply/use, intravenous drug taking, specific sexual behaviours, sexual safety, HIV serostatus, pre-exposure prophylaxis (PrEP) and condom use/non-use may all take place online. These online sociosexual networks and chemsex sexual cultures are disconnected from the commercial gay scene and, therefore, associated health promotion. In addition, difficulties in engaging men via sociosexual media—and in particular men within the chemsex culture—mean that presentations at sexual health and HIV care clinical interactions may provide the …