Primary endpoint Primary analyses for QoL and data were summarized using the mITT population. The WURSS-21 questionnaire was completed at baseline, on each day of treatment and at the last dose used to determine the effect of xylometazoline hydrochloride 0.1% on QoL factors and cold symptoms. Daily WURSS-21 scores were calculated by adding each score of the 10 questions related to symptoms and the 9 questions related to QoL, 19 in total (Supplemental Methods Section 3). Two questions not related to specific symptoms or QoL factors, but overall performance, were not included in the total score. The severity scale range of the different WURSS-21 scores was calculated by multiplying the total number of individual symptom and/or QoL factors by the individual lowest (score = 0), very mild (score = 1), mild (score = 3), moderate (score = 5), and highest (score = 7) severity scores. Thus, the WURSS-21 total score severity ranged from 0 to 133, as the WURSS-21 total score included 19 symptoms and QoL factors. The WURSS-21 total symptom domain severity score ranged from 0 to 70, and the WURSS-21 total QoL domain severity score ranged from 0 to 63. The change from baseline in mean WURSS-21 scores were analyzed each day using a Student’s paired t-test, and p-values were assessed to a significance level of α = 0.05 and 95% confidence intervals (CIs).