Statistical analysis
Statistical analysis was conducted using IBM SPSS 25 for Windows. Discrete variables were presented as counts (percentage) and continuous variables as mean with ±standard deviation (SD) if normally distributed or median with interquartile range (IQR) if not normally distributed. Comparison between groups was performed using the independent samples test if normally distributed and the Mann–Whitney U test if not normally distributed. For comparison between groups with multiple variables, a chi‐square test was used. Within each treatment group, changes in FEV1 and FVC pre and post study medication were analyzed using the Wilcoxon signed rank test. A 