[1] Univ Fed Rio Grande do Sul, Sch Med, Postgrad Program Epidemiol, Porto Alegre, RS, Brazil
[2] Univ Fed Rio Grande do Sul, Hosp Clin Porto Alegre, Porto Alegre, RS, Brazil
[3] Univ N Carolina, Dept Epidemiol, Chapel Hill, NC USA
[4] Univ N Carolina, Dept Biostat, Chapel Hill, NC USA
[5] Univ Sao Paulo, Univ Hosp, Fac Med, Dept Clin Med, Sao Paulo, Brazil
[6] Univ Sao Paulo, Univ Hosp, Ctr Clin & Epidemiol Res, Sao Paulo, Brazil
[7] Univ Fed Minas Gerais, Fac Med, Belo Horizonte, MG, Brazil