[1] Albert Einstein Coll Med, Dept Pediat, Bronx, NY 10467 USA
[2] Albert Einstein Coll Med, Dept Epidemiol & Populat Hlth, Bronx, NY 10467 USA
[3] Albert Einstein Coll Med, Dept Family & Social Med, Bronx, NY 10467 USA
[4] Univ Michigan, Sch Publ Hlth, Dept Epidemiol, Ann Arbor, MI 48109 USA
[5] Univ Calif San Diego, Dept Family & Prevent Med, La Jolla, CA 92093 USA
[6] Univ Pittsburgh, Dept Epidemiol, Pittsburgh, PA 15261 USA
[7] Wake Forest Univ, Bowman Gray Sch Med, Dept Epidemiol & Prevent, Winston Salem, NC USA
[8] Harvard Univ, Brigham & Womens Hosp, Sch Med, Dept Med, Boston, MA 02115 USA