Active collaboration with Dr. Rhonda Szczesniak, Department of Pediatrics, University of Cincinnati, Division of Biostatistics & Epidemiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, United States and the Cystic Fibrosis Foundation.

To evaluate analytic approaches to assess changes in FEV1 decline. We focus on

1 Natural progression of lung function.

2a Lung function progression before and after treatment (ivacaftor) initiation.

2b Between treated and untreated groups of subjects.

3 Variability in lung function decline before and after treatment (ivacaftor) initiation.