[1] Univ Massachusetts, Chan Med Sch, Dept Populat & Quantitat Hlth Sci, Div Prevent & Behav Med, Worcester, MA, Brazil
[2] Univ Massachusetts, Chan Med Sch, Dept Populat & Quantitat Hlth Sci, Hlth Serv Res, Worcester, MA USA
[3] Univ Massachusetts, Chan Med Sch, Dept Populat & Quantitat Hlth Sci, Div Epidemiol, Worcester, MA, Brazil
[4] Univ Massachusetts, Child Hlth Equ Ctr, Chan Med Sch, Dept Pediat, Worcester, MA, Brazil
[5] Populat & Quantitat Hlth Sci, 368 Plantat St, Worcester, MA 01605 USA