[1] Dartmouth Coll, Hitchcock Med Ctr, Norris Cotton Canc Ctr, Dartmouth Med Sch, Lebanon, NH 03756 USA
[2] Dartmouth Coll, Dartmouth Med Sch, Dept Community & Family Med, Lebanon, NH 03756 USA
[3] Montefiore Med Ctr, Albert Einstein Coll Med, Dept Pediat, Bronx, NY 10467 USA
[4] Montefiore Med Ctr, Albert Einstein Coll Med, Dept Microbiol & Immunol, Bronx, NY 10467 USA
[5] Montefiore Med Ctr, Albert Einstein Coll Med, Dept Epidemiol & Populat Hlth, Bronx, NY 10467 USA
[6] Montefiore Med Ctr, Albert Einstein Coll Med, Dept Gynecol & Womens Hlth, Bronx, NY 10467 USA
[7] Harvard Univ, Sch Publ Hlth, Dept Genet & Complex Dis, Boston, MA 02115 USA
[8] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA 94143 USA