Evaluating the impact of the UK’s first saNctioned sAfer drug Consumption faciliTy (ENACT): A mixed-methods natural experiment study

Aim: To evaluate the impact of the UK’s first sanctioned pilot safer drug consumption facility (SDCF) in Glasgow on health, social, community, environmental, and economic outcomes.

Background: There are currently no SDCFs in the UK. While over 100 facilities operate internationally across Europe, North America, and Australia, robust evaluations have generally been lacking and evidence on their population effect remains weak. Following a statement by Scotland’s Lord Advocate in September 2023 that it would not be in the public interest to prosecute anyone using a SDCF, Glasgow City Health and Social Care Partnership (HSCP) is progressing plans to open a pilot SDCF (anticipated in the summer of 2024). The Lord Advocate’s position is conditional on there being “careful and rigorous evaluation of the facility and its effects”. Evaluation is therefore critical to the development of the Glasgow service and could potentially lead to further SCDFs across the UK.

The Glasgow SDCF will be located alongside its Enhanced Drug Treatment Service which has been operational since 2019 and delivers Scotland’s only diamorphine-assisted treatment clinic alongside other therapies. It will provide people who inject drugs (PWID) with a supervised ‘drop-in’ venue where they can use their own drugs under medical supervision and additional support and referral to a broad range of services including wound care, safer injecting advice, blood-borne virus testing, take-home naloxone, Opioid Agonist Treatment (OAT) and other health and social services (e.g. welfare, housing support).

PWID are at high risk of adverse health and social outcomes including bacterial and viral infections, drug-related deaths, suicide and other causes of premature mortality, homelessness, and imprisonment. In Scotland there is a drug-related death (DRD) public health emergency – with some of the highest DRD rates observed globally (at >4% in people out of drug treatment in 2019-20). Glasgow has amongst the highest DRD rates in the country and Glasgow city is also the setting of the largest outbreak of HIV infection among PWID in the UK for over 30 years. Injecting risk and health harms are particularly severe among the estimated 300-500 individuals engaged in public injecting, of a total of up to 1,000 PWID, in Glasgow city centre. Expanding harm reduction and implementing other new approaches to addressing the health and social needs of PWID, particularly those engaged in public injecting, is an urgent priority for the Glasgow City HSCP and Scottish Government - who have committed to funding the operational costs (£2.3m per year) for the duration of the pilot SDCF. Glasgow therefore offers a compelling case for the UK’s first SDCF and its evaluation. Public injecting and excess drug related mortality risk are increasingly being observed in other UK cities, so the results of this study will be highly relevant to public health policy-makers, health care providers and people with lived experience across the UK. The first UK facility also presents an important opportunity, with other international collaborators, to strengthen the evidence on the benefits of SDCF.

Design and methods: We propose a mixed methods natural experiment study combining process evaluation, qualitative methods, population-based surveys, data linkage of administrative data, systematic social observation, mathematical and economic modelling. Our work benefits from strong involvement with the local partners and stakeholders (including the NHS health board, local authority, police etc.) and co-production with the Scottish Drugs Forum and people with lived experience of injecting drugs.

We will deliver this proposal through the following 6 work packages (WPs):

WP0 - System mapping and planning integration. In partnership with Greater Glasgow and Clyde NHS Board, we will characterise the intended service model for the SDCF in Glasgow, identify hypothesised pathways through which impacts may arise and consider how the intervention can be considered a disruption in the broader system of public injecting and how the intervention works with other harm reduction interventions. Our systems map informs the planned work packages and will be updated based on their findings. We will also plan our approach to integration of results across each work package, and our methods to facilitate bringing together each strand of evidence.
WP1 - Process evaluation: We will conduct qualitative interviews with service users, SDCF staff, other related service providers and relevant policy stakeholders to explore the implementation of the intervention, lived experiences of engaging with the service, barriers and facilitators to delivery, and the role of context in shaping intervention delivery. Interview data will be complemented by analysing relevant service documents. Quantitative measures of engagement with the SDCF (including indicators of the numbers of PWID that are being reached and their characteristics), referral pathways and adverse events will also be captured. WP2 - Impact on drug-related behaviours and health outcomes of PWID: We will examine changes in outcomes over time for PWID in Glasgow city pre and post introduction of the SDCF, and for the latter according to intensity of exposure to the intervention, comparing trends to those in other cities that do not have access to a SDCF. We will assess impacts on drug-related behaviours (assessed through a national bio-behavioural survey) and health outcomes (e.g. ambulance call-outs, hospitalisations, deaths ascertained through national linked electronic health records). WP3 - Impact on the immediate and wider community: We will assess potential adverse or beneficial impacts on the broader community in which the SDCF is located. Repeated social surveys of the community and control areas will assess trends in wellbeing, attitudes and perceptions of community safety. Systematic social observation characterises the physical environment over time and will be used to detect potential changes in drug-related litter and other indicators of social and drug disorder. Repeated focus groups will be conducted with members of the local community, including representatives from businesses and local residents, to explore how perceptions evolve as the intervention becomes embedded. Potential adverse consequences on the local economy will be assessed by comparing property values and empty business premises (ascertained through administrative data) in the intervention area, compared to other parts of Glasgow. WP4 – Epidemiological modelling: We will draw on and further develop existing mathematical models of key health harms (DRD and HIV/HCV) in Scotland to assess the contribution and impact SDCF did and could have on preventing these harms separately and in combination with other interventions (including OAT, take-home naloxone, and community Needle and Syringe Programmes). The models will consider the potential impact of expanding SDCF in other settings in Scotland in combination with other interventions.
WP5 – Health economics: Cost-effectiveness analyses will quantify the costs for intervention delivery and value the broad range of health outcomes (e.g. hospital admission, DRDs, transmission of BBV) from a health and social care perspective. A broader cost-benefit analysis will capture the impacts on not just service users, but also the wider community and adopt a societal perspective to quantifying a more holistic set of costs and benefits (including criminal justice). The latter will be important given the role of local authorities and non-health sectors for this intervention.

Potential impact: In addition to major scientific contributions, we anticipate evaluation findings will directly inform plans on whether the Glasgow SDCF is to be continued and decisions by Scottish Government regarding if the model is to be rolled out to elsewhere within Scotland. More broadly, there is substantial interest in implementing similar interventions in the rest of the UK and findings will be disseminated in a timely manner to relevant policy and practitioner groups and hosted events.