Statistical analysis
Results were expressed as median and interquartile range(IQR) or proportions as required. While normality tests were negative, the comparison of continuous variables(PACT, ACT, PAQLQ, FeNO, FEV1, FVC, FEV1/FVC, FEF25%-75%) were performed using Mann-Whitney U test. The percentages of these variables were compared using qhi-square test. Correlation between tests were investigated by Spearman correlation test. The diagnostic value of the PACT, ACT and PAQLQ to detect “well controlled” asthma as defined by GINA was determined by calculation of area under the curve(AUC) of receiver operating characteristic(ROC) curves. The compatibility of the tests with GINA criteria were assessed by kappa test(κ). Statistical significance was defined if p<0.05. Analyses were performed using SPSS statistical software, version 20.0(SPSS Inc, Chicago, Illinois).