Core outcome domains for controlled trials and clinical recordkeeping in eczema: international multiperspective Delphi consensus process.

There is wide variation in the use of outcome measures for eczema. We performed a three-stage web-based international Delphi exercise to develop consensus-based sets of core outcome domains for eczema for "controlled trials" and "clinical recordkeeping". A total of 57 individuals from four stakeholder groups (consumers, clinical experts, regulatory agency representatives, and journal editors) representing 13 countries were asked to rate the importance of 19 outcome domains for eczema and to choose which domains should be included in two core sets of outcomes. Forty-six individuals (81%) participated. Participants received standardized feedback, including the group median, interquartile range, and previous responses, and the assessment was repeated in two subsequent rounds. We defined consensus a priori if at least 60% of the members of at least three stakeholder groups, including consumers, recommended domain inclusion in the core set. Consensus was achieved for inclusion of symptoms, physician-assessed clinical signs, and a measurement for long-term control of flares in the core set of outcome domains for eczema trials. We recommend including these three core outcomes in future eczema trials in order to enhance clinical interpretability and to enable meta-analyses across different studies. For recordkeeping, consensus was reached to regularly monitor eczema symptoms in clinical practice. Future work is needed to select which existing or new scales should be used to measure the domains identified as relevant for the core set.