1. Social Medicine Department, Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
2. School of Medicine, Graduate Program in Pediatrics and Child Health, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
3. Department of Preventive Medicine, Faculty of Medicine FMUSP, Universidade de São Paulo, SP, Brazil