Comparison of Urticaria Activity Score Over 7?Days (UAS7) Values Obtained from Once-Daily and Twice-Daily Versions: Results from the ASSURE-CSU Study

摘要

Abstract Background The Urticaria Activity Score summed over 7?days (UAS7) assesses the itch severity and hive count in chronic spontaneous urticaria (CSU) using once- or twice-daily diary-based documentation. Objective The aim of this study was to evaluate the comparability of twice-daily versus once-daily versions of the UAS and the resulting UAS7 values. Methods Data came from the ASSURE-CSU study. The twice-daily and once-daily UAS7 was calculated from morning and evening ratings, as well as from exact 24-h evening ratings of hive count and itch severity, respectively. Three UAS7 scores were computed: UAS7 twice daily (UAS7~(TD)), UAS7 once daily for maximum itch (UAS7~(OD1MAX)), and UAS7 once daily for average itch (UAS7~(OD2AVG)). UAS7 values were assigned to five score bands (0, 1–6, 7–15, 16–27, 28–42), reflecting urticaria-free to severe disease activity. The score values and score band ratios of the UAS7~(TD)and UAS7~(OD)versions were compared and assessed for correlation by weighted Cohen’s kappa statistics. Results Data from 614 patients were analyzed. All three versions of the UAS7 yielded very similar results, with a mean (standard deviation) UAS7~(TD), UAS7~(OD1MAX), and UAS7~(OD2AVG)of 17.3 (10.49), 17.7 (8.90), and 16.2 (8.68), respectively. Correlation coefficients between UAS7~(TD)and UAS7~(OD1MAX), UAS7~(TD)and UAS7~(OD2AVG), and UAS7~(OD1MAX)and UAS7~(OD2AVG)were 0.94, 0.95, and 0.99, respectively, showing very high positive pairwise correlation. The weighted kappa coefficient, κ (95% confidence interval) was 0.78 (0.75–0.82) for UAS7~(TD)versus UAS7~(OD1MAX), and 0.82 (0.78–0.85) for UAS7~(TD)versus UAS7~(OD2AVG), demonstrating substantial agreement. Conclusions The once- and twice-daily UAS7 scores were highly consistent, supporting the use of either version when evaluating CSU activity.