A core outcome set for efficacy of acute treatment of hereditary angioedema

Background Clinical trials investigating drugs for acute treatment of hereditary angioedema attacks have assessed many different outcomes. This heterogeneity limits comparability of trial results and may lead to selective outcome reporting bias and a high burden on trial participants. Objective To achieve consensus on a Core Outcome Set comprising key outcomes that should ideally be utilized in all clinical efficacy trials involving acute treatment of hereditary angioedema attacks. Methods A Delphi consensus study was conducted involving all relevant parties: hereditary angioedema patients, hereditary angioedema expert clinicians and clinical researchers, pharmaceutical companies, and regulatory bodies. Two internet-based survey rounds were conducted. In round 1, panelists indicated the importance of individual outcomes used in clinical trials on a 9-point Likert scale. Based on these results, a core outcome set was developed and voted on by panelists in round 2. Results Fifty-eight worldwide panelists completed both rounds. The first round demonstrated high importance scores and substantial agreement among the panelists. In the second round, a consensus of ≥90% was achieved on a core outcome set consisting of five key outcomes: change in overall symptom severity at one predetermined time point between 15 minutes and 4 hours after treatment, time to end of progression of all symptoms, need for rescue medication during the entire attack, impairment of daily activities, and treatment satisfaction. Conclusion This international study obtained a high level of consensus on a core outcome set for acute treatment of hereditary angioedema attacks consisting of five key outcomes.