Data analysis will be in both intention-to-treat and per-protocol fashion. A linear mixed-effect regression model will be applied to assess treatment effect on LCQ score, SF-36, and lung function. Within-subject variation will be fitted in the model as random effects whereas the treatment will be considered as a fixed effect. Time at measurement (i.e., 2- and 4-week) will also be included in the mixed model by treating it as fixed-effect. Marginal treatment effects between treatments and time will be then estimated and compared.