Analyses
Quantitative variables are described as mean (SD) or median (IQR) depending on the distribution. Between-group comparisons of continuous variables were analyzed using the nonparametric Wilcoxon 2-sample test. Qualitative variables are reported as proportions with 95% CI and compared using the chi-square test or Fisher exact test, as appropriate. As we expected some patients to experience >1 exacerbation during the follow-up and to exhibit the same behavior in terms of action plan use for each, we chose the generalized estimating equation (GEE) method to compare WAP and DAP use.