Table 1

Core outcome set stakeholder groups and methods of approaching potential participants

Stakeholder group	Selection criteria	Method of approach
Patients and parents	Patients aged 12–18 years who have been treated for acute uncomplicated appendicitis in the preceding 12–24 months. Parents of children (aged 5–18 years) who have been treated for acute uncomplicated appendicitis in the preceding 12–24 months. Families may or may not have participated in CONTRACT. Patient and parent panels will specifically include children and parents treated initially by non-operative management as well as those treated operatively.	Invited to participate via clinical teams from the three sites that are participating in the CONTRACT study. Identified to participate via further participant identification sites.
Paediatric surgeons	All practising consultant paediatric surgeons in the UK who treat children with acute uncomplicated appendicitis will be considered potential participants.	Invited to participate via the mailing list of the British Association of Paediatric Surgeons and through personal contacts of the investigators.
General surgeons	Adult general surgeons in the UK who regularly treat children with acute uncomplicated appendicitis will be considered potential participants. This will include those identified as having an interest in the treatment of children.	Invited to participate via existing personal contacts and through regional paediatric surgical networks within the UK.

CONTRACT, CONservative TReatment of Appendicitis in Children—a randomised controlled Trial (Feasibility).