Complexity in Health, Education, and Social Support for Children and Young People With Life-limiting Conditions.

Children and young people (CYP) with life-limiting conditions represent a growing population with complex care needs that span health, education, and social care systems. These children often have multiple diagnoses, rely on medical technologies, and experience prolonged trajectories of illness. Despite this, care remains fragmented, services are poorly integrated, and definitions of "complexity" are variable, inconsistent, and inadequately reflect the lived experience of families and the perspectives of professionals. The CHESS (Complexity in Health, Education, and Social Support) study aims to develop a shared, evidence-informed understanding of "complexity" in the context of CYP with life-limiting conditions. The study will be delivered by a multi-disciplinary, multisectoral research team and is funded by a National Institute for Health and Care Research (NIHR) Programme Development Grant. This research will provide the foundational work to inform the design and implementation of a future NIHR Programme Grant focused on the development and testing of a child-centred, nationally applicable case mix classification system to support integrated multisector care and resource allocation. This qualitative study involves two stages. Stage 1 consists of semi-structured interviews with (i) CYP aged 5-17 years with a life-limiting condition, (ii) parents/carers (including bereaved parents and parents of children aged under 5 years), and (iii) professionals across healthcare, social care, and education sectors. These interviews aim to elicit stakeholder understandings of "complexity," how it is experienced and enacted in care, and the implications for service access, coordination, and outcomes. Stage 2 comprises a series of stakeholder workshops to review, refine, and synthesise findings from Stage 1 and a parallel realist review. Using consensus methods including the Nominal Group Technique, the workshops will co-develop a cross-sectoral conceptual definition of "complexity" and produce a logic model to guide integrated care delivery for this population. The CHESS study seeks to address a critical evidence gap in how complexity is understood, measured, and supported across systems. By incorporating the voices of children, families, and professionals across sectors, this study will generate new conceptual clarity, build a foundation for improved outcomes, and contribute directly to the national agenda on equity, quality, and integration in paediatric palliative and complex care.

Stage 1 - Interviews Inclusion Criteria: * Children (5-17 years) with any life-limiting condition defined using the UK Together for Short Lives widely adopted 4 categories of life-limiting/life-threatening conditions among children. * Parents/carers of children (0-17 years old) with a life-limiting conditions. * Bereaved parents of a child who had a life-limiting condition (at least 3 months since bereavement). * Healthcare professionals (medicine, nursing, allied health professionals), social care providers, education teaching and therapy staff with \> 6 months experience of caring for children with life-limiting conditions. Exclusion Criteria: * Children unable to communicate via an interview, using 'draw and talk' or play methods, Talking MatsTM, or via their parents. * Children that speak languages not supported by NHS translation services. * Any child or young person for whom the PI believes participation in the study may induce undue psychological distress. * Parents/carers are unable to provide consent/assent to participate in interviews. * Parents/carers that speak languages not supported by NHS translation services. * Parents who are recently bereaved (\