1. Department of Family Medicine, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
2. Department of Pediatric Gastroenterology and Nutrition, School of Medicine, Universidad de Chile, Santiago, Chile
3. Division of Pediatric Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA, USA
4. Department of Public Health, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
5. Division of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile