1. Department of Pediatrics, Division of Pediatric PulmonologyUniversity at BuffaloBuffaloNew York
2. Nationwide Children's HospitalDivision of Pulmonary MedicineColumbusOhio
3. Biostatistics CoreResearch Institute at Nationwide Children's HospitalColumbusOhio
4. Baylor College of Medicine, Department of PediatricsDivision of Gastroenterology, Hepatology, and NutritionHoustonTexas
5. Cystic Fibrosis Foundation Therapeutics Development Network Coordinating CenterSeattle Children's Research InstituteSeattleWashington
6. Department of Pediatrics, Division of Pulmonary and Sleep MedicineUniversity of WashingtonSeattleWashington
7. Cystic Fibrosis FoundationBethesdaMaryland