Research Information System
TURKISH JOURNAL OF PEDIATRICS, vol.66, no.3, pp.297-308, 2024 (SCI-Expanded)
Background. The lung clearance index (LCI) is a sensitive lung function index that is used to detect early lung disease changes in children with cystic fibrosis (CF). This study aimed to define the predictive role of baseline LCI, along with other potential factors on the change in forced expiratory volume in one second (FEV1) during one-year follow-up in CF patients who had a percent predicted (pp) FEV1 >= 80. Methods. LCI was concurrently performed on 57 CF patients who had ppFEV(1) >= 80 at month zero. The ppFEV(1 ) decline was evaluated prospectively during the one year follow up. The primary outcome of ppFEV(1) decline in the study group in one year was dichotomized according to the median value for the decline in ppFEV(1) , which was 3.7. The LCI value predicting ppFEV(1) decline at the end of one year was calculated with receiver operating characteristic curve analysis. Regression analysis was performed. Furthermore, a decision tree was constructed using classification and regression tree methods to better define the potential effect of confounders on the ppFEV1 decline. Results. The LCI value for predicting ppFEV(1) decline >3.7% at the end of one year was 8.2 (area under the curve: 0.80) Multivariable regression analysis showed that the absence of the F508del mutation in at least one allele, LCI >8.2 and initial FEV1 z-score were predictors of a ppFEV(1) decline >3.7 (p<0.001). Factors altering ppFEV(1) decline>3.7% at the end of one-year evaluated by decision trees were as follows: initial FEV1 z-score, type of CFTR mutation, LCI value and initial weight-for-age z-score. Conclusions. LCI is sensitive for predicting ppFEV(1) decline in patients with ppFEV(1) >= 80 along with the initial FEV1-z-score 1-z-score and type of CFTR mutation.