1. Federal University of Rio Grande do Sul; Social Medicine/Epidemiology; Jose de Alencar 1244, 1009 Menino Deus Porto Alegre Rio Grande do Sul Brazil 90880-480
2. Hospital Femina - Grupo Hospitalar Conceicao; Dinarte Ribeiro 212/83 Porto Alegre Rio Grande do Sul Brazil 90570-150
3. Faculty of Medicine at Federal University of Rio Grande do Sul; Social Medicine; Ramiro Barcelos 2300 Porto Alegre Rio Grande do Sul Brazil 90035-000
4. Universidade Federal do Rio grande do Sul (UFRGS); Departmento de Estatistica, Instituto de Matematica; Av. Bento Goncalves 9500 Porto Alegre Brazil 91501-970
5. The University of Manchester; Cochrane Oral Health Group, School of Dentistry; Coupland III Bldg, Oxford Rd Manchester UK M13 9PL
6. University of Tesside and South Cleveland Hospital, Middlesbrough; Gynaecological Surgery; 94 Westgate Guisborough Yorkshire UK TS14 6AP
7. Universidade do Extremo Sul Catarinense; Medical School; Av. Universitaria, 1105-Bairrio Universitario- Criciuma Criciuma Santa Catarina Brazil 88806-000
8. Universidade Federal de Ciências da Saúde; Department of Public Health; Ulbra and Grupo Hospitalar Conceição Porto Alegre Brazil 9