There are fewer than 30 paediatric intensive care units (PICUs) in the United Kingdom (UK). This means that a critically ill child taken to their nearest hospital will need to be transferred to a PICU. Such transports are usually done by PICU retrieval teams (PICRTs), mobile teams who take specialist expertise to the child and safely transport them to a PICU.

There are national variations in how PICRTs are organised and deliver clinical care. There has been little research into these differences and how they might influence outcomes and experiences for sick children and families. The investigators do not know if national variation in how PICRT services are organised and delivered matters, or whether current standards help achieve the best outcomes for patients. This clinical study aims to understand how existing differences in access to paediatric intensive care and care provided by PICRTs affect clinical outcomes and experiences for transported critically ill children and families. The investigators will analyse routine national audit data to examine various aspects such as how long it takes a PICRT to reach the patient, how long it takes the child to reach the PICU, the seniority of clinicians performing the transport, medical procedures performed by the PICRT and any critical incidents during transport, and investigate whether any of these factors influence how likely a child is to survive. The investigators will also collect and analyse information about the experiences of sick children by interviewing the families involved, and staff experiences of PICU retrieval by interviewing clinicians. Alongside this work, the investigators will look at the costs of different ways of delivering PICRT services for sick children, and use mathematical techniques to study if and how alternate models of service delivery can improve clinical outcomes in a cost effective manner. The research team in this trial includes PICU and transport clinicians, parents, academic experts and an National Health Service (NHS) commissioner.

Independent committees consisting of clinicians and parents will be formed to oversee the study. The work from this study will directly inform the development of evidence-based national standards for PICU transport and help improve the patient experience for critically ill children and their families.

Inclusion Criteria:

• Children and young people (age <16 years) transported by a PIC retrieval team for emergency admission to a paediatric intensive care unit in England and Wales.

Exclusion Criteria:

• None

Children and young people (age <16 years) transported by a PIC retrieval team for emergency admission to a paediatric intensive care unit in England and Wales.