A core outcome set for childhood epilepsy treated with ketogenic diet therapy (CORE-KDT study): International parent and health professional consensus.

OBJECTIVE: Ketogenic diet therapy (KDT) can result in benefits (seizure-related and non-seizure-related) for children with drug-resistant epilepsy. However, clinical trials report a wide range of outcomes, making synthesis of evidence difficult, and do not adequately reflect parent views on important outcomes for their child. To address this, we established the first international parent, health professional, and researcher consensus to develop a core outcome set, guided by the Core Outcome Measures in Effectiveness Trials (COMET) Initiative (COMET registration #1116). METHODS: Ethical approval was granted (London-Surrey REC19/LO/1680). A scoping review and interviews with parents identified a comprehensive list of potentially important outcomes, followed by a two-round online Delphi survey of parents and health professionals to prioritize outcomes of importance for inclusion in a core outcome set. This informed a stakeholder consensus meeting and consultation process to finalize the core outcome set. RESULTS: In total, 97 outcomes were identified; 90 from the scoping review and seven from parent interviews. These were rationalized to 77 by the study advisory group, then rated in the first Delphi round by 49 parents and 96 health professionals, who suggested 12 new outcomes for rating in Round 2. Sixty-six percent of participants (30 parents and 66 professionals) completed Round 2, where 22 outcomes met criteria for inclusion. In the consensus meeting (nine parents and 13 professionals), 27 undecided outcomes were discussed and scored; one further outcome reached consensus for inclusion. After consultation and ratification, 14 outcomes across five domains were included in the core outcome set. SIGNIFICANCE: A core outcome set for childhood epilepsy treated with KDT has been developed, incorporating the views of international parents and professionals. Implementation in research and clinical settings will standardize outcome selection and reporting, facilitate data synthesis, and ultimately enhance the relevance of outcomes to parents, researchers, and health professionals.