A Core Outcome Set for Clinical Trials in Pediatric Functional Abdominal Pain Disorders

Objective: To ensure consistency and reduce outcome measure reporting heterogeneity in clinical trials on pediatric functional abdominal pain disorders (FAPDs), a core outcome set (COS) was developed for pediatric FAPD trials. Study design: A mixed-method 2-round Delphi technique was used and key stakeholders, including healthcare professionals (HCPs), patients with FAPD, and their parents were invited to participate. In the first round, key stakeholders identified outcomes of importance through an open-ended questionnaire. Outcomes mentioned by ≥10% of the participants were included in a shortlist. In the second round, this shortlist was rated and prioritized. During a consensus meeting with an expert panel, the final COS was defined. Results: The first round was completed by 152 of 210 (72%) HCPs, 103 (100%) parents, and 50 of 54 (93%) patients. A total of 104 from 167 (62%) HCPs, 102 (100%) parents, and 53 (100%) patients completed round 2. Pain intensity, pain frequency, quality of life, school attendance, anxiety/depression, adequate relief, defecation pattern (disease specific, irritable bowel syndrome), and adverse events were included in the final COS for FAPDs. Conclusion: A set of 8 core outcomes has been identified that should minimally be measured in pediatric FAPD trials. Implementation of the use of this COS will increase comparison between studies and, therefore, improve management of children with FAPDs.