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 disease control and changes in QOL among patients with CU using data from the ongoing observational AWARE study.
MATERIALS/METHODS: Self-reported data from visit 1 (baseline) to visit 4 (9 month period) among CU patients residing in Europe were analysed as measured by the Dermatology Life Quality Index (DLQI; scored 0-30, higher scores represent greater QOL impairment) and the Urticaria Control Test (UCT; scored 0-16, higher scores represent greater disease control; a cutoff score of >12 indicates well-controlled disease). Patients were aged 18 years or older and refractory to at least one course of H1-antihistamines. Growth mixture modelling (GMM) was applied to DLQI data, to analyse change across time and to identify subgroups of patients with differential DLQI response. Once subgroups were identified, the UCT data were analysed using the DLQI subgroup identifier as a grouping variable, to identify changes in UCT scores within each DLQI subgroup. Since the AWARE study is ongoing, the data are currently incomplete and a full information maximum likelihood procedure was applied.
RESULTS: The GMM of DLQI scores identified 6 subgroups of patients. Subgroup 1 (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]). UCT scores within this subgroup were 9.1 (0.1) at visit 1, and 12.0 (0.2) at visit 4, indicating an improvement to well-controlled disease. Subgroup 2 (n=369; 10.1%) had DLQI scores that indicate a moderate effect of CU on QOL (visit 1 = 7.8 [0.6], visit 4 = 10.4 [0.7]); corresponding UCT scores were 7.2 (0.2) at visit 1 and 6.4 (0.3) at visit 4. Subgroup 3 (n=189; 5.2%) had DLQI scores that indicate a very large effect of CU on QOL (visit 1 = 12.1 [0.6], visit 4 = 19.6 [0.9]); corresponding UCT scores were 6.3 (0.3) at visit 1 and 2.6 (0.5) at visit 4. Subgroup 4 (n=103; 2.8%) had DLQI scores that indicate an extremely large effect of CU on QOL (visit 1 = 21.2 [0.8], visit 4 = 26.5 [1.9]); corresponding UCT scores were 3.5 (0.3) at visit 1 and 0.0 (0.8) at visit 4. Subgroup 5 (n=390; 10.7%) had a visit 1 DLQI mean of 15.7 (2.0) (very large effect on QOL) and visit 4 mean of 0 (1.1) (no effect); corresponding UCT scores were 4.0 (0.2) at visit 1 and 14.0 (0.4) at visit 4, indicating an improvement to well-controlled disease. Finally, subgroup 6 (n=123; 3.4%) had a visit 1 DLQI mean of 20.1 (2.3) (very large effect) and visit 4 mean of 6.2 (2.9) (moderate effect); corresponding UCT scores were 3.0 (0.2) at visit 1 and 8.3 (0.5) at visit 4.
CONCLUSIONS: CU has a large effect on quality of life. Improvements in QOL are directly related to improved disease control.
