[1] Univ Calif San Francisco, Dept Pediat, 550 16th St, 4th Floor, POB 0503, San Francisco, CA 94143 USA
[2] Univ Alabama Birmingham, Dept Epidemiol, 1665 Univ Blvd, Birmingham, AL 35233 USA
[3] SRI Int, Ctr Hlth Sci, 333 Ravenswood Ave, Menlo Pk, CA 94025 USA
[4] Univ Witwatersrand, Sch Physiol, 1 Jan Smuts Ave, ZA-2000 Johannesburg, South Africa
[5] Univ Calif San Diego, Exercise & Phys Activ Resource Ctr, 9500 Gilman Dr, Dept 0811, La Jolla, CA 92093 USA
[6] Univ Calif San Diego, Ctr Wireless & Populat Hlth Syst, 9500 Gilman Dr, La Jolla, CA 92093 USA
[7] La Jolla Univ Calif, Herbert Wertheim Sch Publ Hlth & Human Longev Sci, 9500 Gilman Dr, La Jolla, CA 92093 USA
[8] Univ Toronto, Factor Inwentash Fac Social Work, 27 Kings Coll Cir, Toronto, ON M5S 1A1, Canada
[9] 550 16th St, 4th Floor, POB 0503, San Francisco, CA 94143 USA