Background: Prevention of drugs use and related problems is a key activity of the European Union Drugs Agency, which disseminates evidence, trains practitioners, and monitors practices to support evidence-based interventions. However, monitoring prevention availability is complex, as activities are scattered across schools, communities, workplaces, and other settings. National Focal Points (NFPs) - gathered data were complemented by structured expert opinion to better understand actual prevention interventions across Europe.

Methods: We piloted a structured expert knowledge elicitation technique, consulting national experts indicated by volunteering NFPs from Spain, Poland, and Greece. This innovative approach aimed to systematically identify and engage experts to gather insights on local prevention strategies.

Results: Our findings revealed significant variability in expert judgements within and between countries, emphasizing the critical role of facilitated discussions and carefully crafted questions in clarifying sources of variability and uncertainty.

Conclusion: This pilot demonstrates that structured elicitation can feasibly complement routine monitoring of prevention activities - not replacing surveillance and evaluation, but helping interpret and prioritize data collection, refine indicators, and inform planning in complex, multi-setting systems. Future work should test the approach with more diverse experts across additional countries and settings, and triangulate elicited judgements with administrative and evaluation data to strengthen external validity and usability.