[1] Univ Pittsburgh, Dept Behav & Community Hlth Sci, Grad Sch Publ Hlth, 6129 Publ Hlth Bldg,130 De Soto St, Pittsburgh, PA 15261 USA
[2] Univ Pittsburgh, Dept Pediat, Sch Med, 120 Lytton Ave, Pittsburgh, PA 15213 USA
[3] Univ Pittsburgh, Dept Pediat, Sch Med, Suite 225,120 Lytton Ave, Pittsburgh, PA 15713 USA
[4] Univ Pittsburgh, Grad Sch Publ Hlth, POB 7319, Pittsburgh, PA 15213 USA
[5] Prevent Res Ctr, 1516 East Franklin St, Chapel Hill, NC 27514 USA
[6] Univ Texas Austin, Populat Res Ctr, Dept Human Dev & Family Sci, 108 E Dean Keeton St, Austin, TX 78712 USA
[7] UPMC Childrens Hosp Pittsburgh, Univ Ctr, Div Adolescent & Young Adult Med, Suite 3024,120 Lytton Ave, Pittsburgh, PA 15213 USA
[8] Univ Pittsburgh, Univ Ctr, Sch Med, Dept Pediat, Suite 302-2,120 Lytton Ave, Pittsburgh, PA 15213 USA