[1] Univ Fed Rio Grande do Sul, Post Grad Program Epidemiol, Porto Alegre, RS, Brazil
[2] Univ Fed Rio Grande Do Sul, Stat Dept, Porto Alegre, RS, Brazil
[3] Univ Fed Bahia, Post Grad Program Collect Hlth, Salvador, BA, Brazil
[4] Univ Fed Minas Gerais, Fac Med, Belo Horizonte, Brazil
[5] Univ Fed Minas Gerais, Hosp Clin, EBSERH, Belo Horizonte, Brazil
[6] Univ Fed Rio Grande do Sul, Post Grad Program Epidemiol, Porto Alegre, RS, Brazil
[7] Univ Fed Rio Grande do Sul, Hosp Clin Porto Alegre, Porto Alegre, RS, Brazil
[8] Hosp Clin Porto Alegre, Clin Res Ctr, Av Protasio Alves 211-St Cecilia, BR-90035903 Porto Alegre, RS, Brazil