1. Pontificia Universidad Javeriana; Department of Clinical Epidemiology and Biostatistics, Faculty of Medicine; Cr. 7 #40-62, 2nd floor Bogotá DC Colombia
2. Faculty of Medicine, Pontificia Universidad Javeriana; Department of Internal Medicine; Bogotá Colombia
3. Fundacion Cardioinfantil Instituto de Cardiologia; Research Department; Bogota Colombia
4. BMJ; BMJ-TAG; Tavistock Square London UK WC1H 9JR