[1] Univ Michigan, Ctr Managing Chron Dis, Ann Arbor, MI 48109 USA
[2] Univ Penn, Sch Med, Philadelphia, PA 19104 USA
[3] Pardee RAND Grad Sch, Santa Monica, CA USA
[4] Merck Childhood Asthma Network, Washington, DC USA
[5] Univ Illinois, Sch Publ Hlth, Chicago, IL USA
[6] Los Angeles Unified Sch Dist, Los Angeles, CA USA