Statistical Analysis
First, to compare SpWB and QoL between the 2 groups (subjects with controlled CU and those with not controlled CU), univariate analyses were performed using a Mann-Whitney U test. Association between SpWB, QoL and disease control was assessed by Spearman’s rank correlation coefficient.
Nonparametric models were performed because the scores had a non-Gaussian distribution, according to the rejection of the hypothesis by the Shapiro-Wilk normality test. A p value of < 0.05 was regarded as statistically significant. All statistical analyses were performed using SAS® System statistical software, version 6.11 (SAS Institute, Inc., Cary, North Carolina).