Development and validation of the Urticaria Control Test: A patient-reported outcome instrument for assessing urticaria control

Background: Chronic urticaria is a frequent and debilitating skin disease. Its symptoms commonly fluctuate considerably from day to day. As of yet, the only reliable tool to assess disease activity is the Urticaria Activity Score, which prospectively documents the signs and symptoms of urticaria for several days. Objective: We sought to develop and validate a novel patient-reported outcome instrument to retrospectively assess urticaria control, the Urticaria Control Test (UCT). Methods: Potential UCT items were developed by using established methods (literature research and expert and patient involvement). Subsequently, item reduction was performed by using a combined approach, applying impact and regression analysis. The resulting UCT instrument was then tested for its validity, reliability, and screening accuracy. Results: A 4-item UCT with a recall period of 4 weeks was developed based on 25 potential UCT items tested in 508 patients with chronic urticaria. A subsequent validation study with the 4-item UCT in 120 patients with chronic urticaria demonstrated that this new tool exhibits good convergent and known-groups validity, as well as excellent test-retest reliability. In addition, the screening accuracy to identify patients with urticaria with insufficiently controlled disease was found to be high. Conclusions: The UCT is the first valid and reliable tool to assess disease control in patients with chronic urticaria (spontaneous and inducible). Its retrospective approach and simple scoring system make it an ideal instrument for the management of patients with chronic urticaria in clinical practice.