City Checking: Piloting the UK's first community-based drug safety testing ('drug checking') service in two city centres.

Aims: To explore the feasibility of delivering community-based drug safety testing ('drug checking'), to trial service design characteristics and to compare with festival-based testing.

Methods: 171 substances of concern were submitted on five dates at three venues in two UK cities and tested using up to six analytical techniques. Test results and harm reduction advice were distributed directly to over 200 service users through 144 tailored healthcare consultations, to stakeholders, and through early warning systems, media and social media alerts.

Results: 171 samples were submitted and identified as MDMA (43.3%), cocaine (12.9%), ketamine (12.9%), various psychedelics submitted by students, and heroin and a synthetic cannabinoid submitted by rough sleeping communities, with 76% of samples' test results as expected. 144 primary service users identified as 91.7% white, 68.1% male, with an average age of 26.7 years. Reported harm reduction intentions included alerting friends and acquaintances (37.5%), being more careful mixing that substance (35.4%), lowered dosage (27.8%), disposal of further substances (6.9%), and additionally 2.8% handed over further substances for verified destruction.

Conclusion: Community-based drug safety testing ('drug checking') was piloted for the first time in the UK - within a drugs service, a community centre and a church - with consideration given to meso-level operational feasibility and micro-level behavioural outcomes. Service design characteristics such as venue, day of week, prior publicity, service provider, and direct and indirect dissemination of results all may impact on outcomes. Future studies should consider cost-benefit analyses of community and event-based testing and context-appropriate macro, meso and micro-level evaluations.