OBJECTIVES: To assess whether three patient-reported outcomes (PRO) instruments are equally informative about response to treatment for chronic spontaneous urticaria (CSU). PRO instruments compared included: Urticaria Activity Score (UAS7 - measuring daily pruritus scores and number of hives summed over 7 days for a weekly score); Dermatology Life Quality Index (DLQI) (10-item PRO with one-week recall assessing the impact of skin disease); and Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL) (23-item PRO with 2-week recall measuring urticaria-specific HRQoL through rating of symptoms and their impact on aspects of life).
METHODS: Data come from three phase 3 clinical trials investigating the effects of omalizumab for patients with refractory CSU. PRO data were collected at baseline and weeks 4, 12, 24, and 40 (ASTERIA I and GLACIAL), and baseline and weeks 4, 12, and 28 (ASTERIA II). Data were analysed using latent growth models (LGMs), irrespective of treatment. For each trial, correlations between changes in UAS7 and the other PROs were examined to investigate how closely dermatologic-related and urticaria-specific QoL changes mirrored symptom changes.
RESULTS: In all trials, mean UAS7 score was 30 out of 42, corresponding to a large effect on patient’s dermatologic-related HRQoL (DLQI mean score=12 out of 30) and above-median disease-specific HRQoL (CU-Q2oL median score=43 out of 100). Over the course of each trial, changes in symptom and HRQoL scores were evident [4-15 scale points, depending on PRO]. LGMs found changes in symptoms and HRQoL were highly correlated: 0.88, 0.85 and 0.88 (for each trial, respectively) between DLQI and UAS7; 0.94, 0.93 and 0.90 (for each trial, respectively) between CU-Q2oL and UAS7.
CONCLUSIONS: Collecting HRQoL information in-clinic (DLQI & CU-Q2oL) can provide an excellent indication of weekly UAS7 symptom scores. Results suggest that clinicians have a choice of instrument for assessing patient response to treatment.
