Realist Process Evaluation of the implementation and impact of an organisational cultural transformation programme in the Children and Young People's Secure Estate (CYPSE) in England: study protocol.

INTRODUCTION: Young people in contact with the youth justice system are more likely to present with complex ongoing needs than young people in the general population. To address this, the Framework for Integrated Care (SECURE STAIRS) is being implemented in the Children and Young People's Secure Estate: a 'whole systems' approach to support secure settings to develop trauma-informed and relationally based environments, supporting staff to provide consistent, therapeutic care. This paper aims to present the protocol for a national cohort study examining the impact and implementation of this cultural transformation programme. METHODS AND ANALYSIS: A mixed-methods realist evaluation will be conducted. Data collection will take place between August 2018 and December 2020. Eighteen sites will collect routine service activity data and questionnaires completed by young people, parents/guardians and staff. Semi-structured interviews and non-participant observations will be conducted across five qualitative focus sites with young people and staff. An economic evaluation will examine value for money. The results will be triangulated at the analysis stage to gain an in-depth understanding of experiences. ETHICS AND DISSEMINATION: Ethical approval was granted by the Health Research Authority, Her Majesty's Prison and Probation Service and UCL Ethics Committee. Findings will be disseminated via project reports, site feedback, peer-reviewed journal publications and conference presentations.