Background: Chronic spontaneous/idiopathic urticaria (CSU/CIU), defined as the occurrence of daily or almost daily wheals/hives, pruritus and/or angioedema for more than 6 weeks without an identifiable external trigger, has a detrimental effect on patient’s health. Health status and outcomes can be measured with the EuroQol (EQ&n5D), a generic, standardized patient-reported outcomes instrument comprised of 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. A descriptive profile is created and a single preference value called utility can be calculated for each profile. The maximum utility value is 1 (perfect health), 0 corresponds to death..
Objective: To assess the EQ–5D utility scores associated with each health state in CSU.
Method: Pooled patient level data from 3 randomised trials (ASTERIA I, ASTERIA II and GLACIAL) evaluating effect of omalizumab on symptoms of refractory CSU/CIU were used to derive utilities. Health status was assessed by patients using EQ-5D at baseline, weeks 12 and at end of the studies; patients also completed a daily diary to assess disease activity (urticaria activity score [UAS]) for their itch and number of hives. Weekly UAS scores (UAS7) range from 0 (no symptoms) to 42 (maximum symptoms). Mean utilities were calculated by a mixed-effects model for the following five health states, defined with UAS7 scores: severe urticaria: UAS7=28-42; moderate: UAS7=16-27; mild: UAS7=7-15; well-controlled urticaria: UAS7=1-6; and urticaria-free: UAS7=0.
Results: Based on this analysis, mean EQ–5D utility scores were obtained for each of the five health states: 0.71 (SD: 0.31) for severe urticaria, 0.78 (0.26) for moderate, 0.85 (0.24) for mild, 0.86 (0.24) for well-controlled and 0.90 (0.25) for urticaria-free.
Conclusion: This is the first study known to derive utilities for CSU/CIU health states. It was observed that among patients in the five health states, those who were urticaria-free reported the highest EQ–5D utility scores, reflecting a better quality of life, with progressively lower utilities for worse health states.
