1. Universidade do Estado do Pará; Public Health; Travessa Perebebuí, 2623 Belém Pará Brazil 66087-670
2. McMaster University; Department of Surgery, St. Joseph's Healthcare Hamilton; 50 Charlton Avenue East Hamilton ON Canada L8N 4A6
3. Federal University of Sao Paulo; Discipline of Preventive Medicine; Rua dos Otonis, 731 Vila Clementino Sao Paulo (Southeast) Brazil 04025-002
4. Universidade Federal de São Paulo / Escola Paulista de Medicina; Brazilian Cochrane Centre; Rua Pedro de Toledo 598 Vila Clementino São Paulo SP Brazil CEP 04039-001
5. Universidade Federal de São Paulo; Emergency Medicine and Evidence Based Medicine; Rua Pedro de Toledo 598 São Paulo São Paulo Brazil 04039-001