[1] Univ ofPittsburgh, Sch Publ Hlth, Dept Epidemiol, Pittsburgh, PA USA
[2] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Behav & Community Hlth Sci, Pittsburgh, PA USA
[3] Chron Dis & Injury Prevent Program, Allegheny Cty HealthDepartment, Pittsburgh, PA USA
[4] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Epidemiol, 130 DeSoto St,5130, Pittsburgh, PA 15261 USA