[1] UCONN Hlth Farmington, Dept Pediat, Farmington, CT USA
[2] Ctr Dis Control & Prevent, Natl Ctr Hlth Stat, Hyattsville, MD 20782 USA
[3] US PHS, Rockville, MD USA
[4] NIEHS, Div Intramural Res, NIH, POB 12233, Res Triangle Pk, NC 27709 USA
[5] San Diego Med Ctr, Dept Allergy, Kaiser Permanente, San Diego, CA USA
[6] Harvard Med Sch, Dept Pediat, Cambridge, MA USA
[7] Social & Sci Syst, Durham, NC USA
[8] Johns Hopkins Univ, Sch Med, Dept Med, Baltimore, MD 21205 USA
[9] Virginia Commonwealth Univ, Dept Family Med & Populat Hlth, Richmond, VA USA
[10] Univ Colorado, Sch Med, Aurora, CO USA
[11] NIOSH, Ctr Dis Control & Prevent, Morgantown, WV USA
[12] Univ N Carolina, Dept Epidemiol, Chapel Hill, NC 27515 USA