1. Department of Pediatric Pulmonology, School of Medicine Pontificia Universidad Catolica de Chile Santiago Chile
2. School of Medicine Pontificia Universidad Catolica de Chile Santiago Chile
3. Department of Public Health, School of Medicine Pontificia Universidad Catolica de Chile Santiago Chile
4. Division of Pulmonary Medicine Perelman School of Medicine at the University of Pennsylvania, Sleep Center, The Children's Hospital of Philadelphia Philadelphia Pennsylvania USA