Fig 4. Comparisons of the frequency of asthma exacerbation (the primary endpoint) between the intervention and control group (Fig 4A for overall intervention and control group and Fig 4B for individual strata) during the 12 months prior to the trial and the 12-month trial.

A. Comparison between overall intervention and control group. B. Comparison between intervention and control group at pre-trial and trial by stratum.