Characteristics of patients with asthma, according to age group.^*

<p>* Plus—minus values are means ±SD. BMI denotes body mass index, GERD gastroesophageal reflux disease, FEV1 forced expiratory volume in 1 second, FVC forced vital capacity, PC20 for methacholine the concentration of inhaled methacholine causing a 20% reduction in FEV1, FENO fraction of exhaled nitric oxide, and BAL broncho-alveolar lavage.</p><p>^† P values are for the comparison of older asthma with the young adult asthma group and were calculated with the use t-test for approximately normally distributed clinical characteristics, Pearson's chi-squared test for differences in proportions, and Wilcoxon signed rank test for all other variables.</p><p>Characteristics of patients with asthma, according to age group.^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133490#t001fn001" target="_blank">*</a>}