Implementing Population Health Management (PHM) Across an Integrated Care System in England, Using Action Learning Sets and an Embedded, Formative Process Evaluation.

Introduction: Population Health Management (PHM) is a UK priority for Integrated Care Systems (ICSs), aiming to deliver proactive, preventative, person-centred care using integrated health and care datasets. However, evidence on implementation in primary care remains limited. Methods: This comparative case study used embedded researchers, ethnography, interviews, and observations to formatively evaluate a 24-month PHM programme across 31 Primary Care Networks in one ICS. Data were thematically analysed using Excel and NVivo, with findings fed back to participants to guide programme delivery. Results: Around 200 stakeholders participated in Action Learning Sets, fostering cross-sector collaboration within four localities. Few innovations, developed using integrated datasets, progressed to delivery, limiting their impact on patient health. While PHM infrastructure was established, delivery was constrained by operational pressures, data governance challenges, limited resources, lack of strategic integration and the nature of local relationships. Discussion: Effective PHM implementation requires more than infrastructure and governance. It depends on developing system-wide soft skills (facilitation, co-production), motivating stakeholders, and investing in processes that support insight generation, innovation piloting, and evidencing of impact. Conclusion: The study highlights the need for stronger strategic integration, sustained resourcing, coordination, and co-production to realise PHM's potential at system, place and neighbourhood levels in addressing health inequalities and improving population outcomes.