INTRODUCTION: Chronic urticaria (CU) is characterised by the repeated occurrence of itchy and sometimes painful hives and/or angioedema for 6 weeks or longer and can have a substantial impact on quality of life (QOL). This study evaluated the effect of CU on QOL and the association with the presence of angioedema using data from the ongoing observational AWARE study.
MATERIALS/METHODS: Self-reported QOL data from visit 1 (baseline) to visit 4 (9 month period) measured by the Dermatology Life Quality Index (DLQI) among CU patients residing in Europe were analysed. Patients were aged 18 years or older and refractory to at least one course of H1-antihistamines. A longitudinal modelling technique (growth mixture modelling [GMM]) was applied to the data. This method analyses individual-level change across time and identifies subgroups of patients with differential response. Since the AWARE study is ongoing, the data are currently incomplete and a full information maximum likelihood procedure was applied. Comparisons between subgroups using chi-square tests were made using demographic and clinical characteristics.
RESULTS: The GMM identified 6 subgroups of patients with differential response. The largest subgroup (n=2,472; 67.8% of the sample) had sustained low DLQI scores, indicating a small effect of CU on QOL (mean [SD] visit 1 = 5.0 [0.4], visit 4 = 3.0 [0.4]). This large subgroup remains heterogeneous and will be further analysed for presentation. A moderate effect was found in 10.1% of the sample (n=369) (visit 1 = 7.8 [0.6], visit 4 = 10.4 [0.7]), a very large effect was found in 5.2% (n=189) (visit 1 = 12.1 [0.6], visit 4 = 19.6 [0.9), and an extremely large effect was found in 2.8% (n=103) (visit 1 = 21.2 [0.8], visit 4 = 26.5 [1.9]). Two further subgroups emerged who improved over time: 10.7% of the sample (n=390) had a visit 1 mean of 15.7 [2.0] (very large effect on QOL) and visit 4 mean of 0 [1.1] (no effect); in 3.4% of the sample (n=123) corresponding means were 20.1 [2.3] (very large effect) and 6.2 [2.9] (moderate effect). The small effect subgroup had a higher proportion of males compared to the remaining subgroups (32% vs. 20-17%; P=0.001). Patients in the small effect subgroup (n=2,472) and the moderate effect subgroup (n=369) were less likely than the remaining subgroups to have angioedema at baseline (39.9% and 39.3% vs. 53.1%-59.2%; P<0.001). Patients in the small effect subgroup (n=2,472) and the subgroup with DLQI scores that changed from very large to no effect (n=390) were less likely than the remaining subgroups to have angioedema at visit 4 (4.0% and 4.1% vs. 10.7%-14.6%).
CONCLUSIONS: CU has a large effect on quality of life. Poor QOL is associated with the presence of uncontrolled angioedema.
