SUMMARY OF BACKGROUND DATA: A previous systematic review identified 115 outcomes in 60 trials and systematic reviews evaluating treatments for children with appendicitis, suggesting the need for a COS.
METHODS: The development process consisted of 4 phases: (1) an updated systematic review identifying all previously reported outcomes, (2) a 2-stage international Delphi study in which parents with their children and surgeons rated these outcomes for inclusion in the COS, (3) focus groups with young people to identify missing outcomes, and (4) international expert meetings to ratify the final COS.
RESULTS: The systematic review identified 129 outcomes which were mapped to 43 unique outcome terms for the Delphi survey. The first-round included 137 parents (8 countries) and 245 surgeons (10 countries), the second-round response rates were 61% and 85% respectively, with 10 outcomes emerging with consensus. After 2 young peoples' focus groups, 2 additional outcomes were added to the final COS (12): mortality, bowel obstruction, intraabdominal abscess, recurrent appendicitis, complicated appendicitis, return to baseline health, readmission, reoperation, unplanned appendectomy, adverse events related to treatment, major and minor complications.
CONCLUSION: An evidence-informed COS based on international consensus, including patients and parents has been developed. This COS is recommended for all future studies evaluating treatment ofsimple appendicitis in children, to reduce heterogeneity between studies and facilitate data synthesis and evidence-based decision-making.
METHODS AND ANALYSIS: A long list of outcomes will be generated using (1) a systematic review of existing studies on OA-TOF and (2) qualitative research with children (patients), adults (patients) and families involving focus groups, semistructured interviews and self-reported outcome activity packs. A two-phase Delphi survey will then be completed by four key stakeholder groups: (1) patients (paediatric and adult); (2) families; (3) healthcare professionals; and (4) researchers. Phase I will include stakeholders individually rating the importance and relevance of each long-listed outcome using a 9-point Likert scale, with the option to suggest additional outcomes not already included. During phase II, stakeholders will review summarised results from phase I relative to their own initial score and then will be asked to rescore the outcome based on this information. Responses from phase II will be summarised using descriptive statistics and a predefined definition of consensus for inclusion or exclusion of outcomes. Following the Delphi process, stakeholder experts will be invited to review data at a consensus meeting and agree on a COS for OA-TOF.
ETHICS AND DISSEMINATION: Ethical approval was sought through the Health Research Authority via the Integrated Research Application System, registration no. 297026. However, approval was deemed not to be required, so study sponsorship and oversight were provided by Alder Hey Children's NHS Foundation Trust. The study has been prospectively registered with the COMET Initiative. The study will be published in an open access forum.