Supplementary information files for "A stakeholder‐informed approach to the development and implementation of national digital registry and learning healthcare system ( LHS ) for psychosis: findings from the EPICare platform"

Using participatory co‐design, we conducted four multi‐stakeholder workshops and preparatory lived experience sessions with people with lived experience, clinicians, informaticians, academics, and policymakers. We identified essential data elements using adapted “MoSCoW” card sort methodology, refined content, and developed dashboard requirements. Parallel informatics and implementation research assessed technical feasibility, data maturity, and harmonisation requirements and evaluated anticipated barriers and facilitators to future adoption.</p><p dir="ltr"><b>Results</b> Consensus was achieved on core EPICare dataset “must haves” including sociodemographic variables, routine treatment interventions, Patient‐ and Clinician‐Reported Outcome Measures, and longitudinal symptom data.

Stakeholders defined key dashboard features, prioritising usability and alignment with clinical workflow. Substantial variation in Trust‐level data infrastructure informed flexible technical architecture to mitigate implementation risk. Conclusion EPICare stakeholder engagement delivered the blueprint for a co‐designed, technically feasible and nationally scalable specification for a psychosis learning healthcare system, enabling progression to platform development and piloting across five Early Intervention in Psychosis services in the NHS.<br><br>© The Author(s), CC BY 4.0</p>