[1] Univ Washington, Dept Global Hlth, Hans Rosling Ctr Box 351620,3980 15th Ave NE, Seattle, WA 98195 USA
[2] Univ Washington, Dept Biobehav Nursing & Hlth Informat, Seattle, WA 98195 USA
[3] Kenya Govt Med Res Ctr, Nairobi, Kenya
[4] Kenyatta Natl Hosp, Nairobi, Kenya
[5] Univ Washington, Child Family & Populat Hlth, Seattle, WA 98195 USA
[6] Univ Washington, Dept Epidemiol, Seattle, WA 98195 USA
[7] Univ Washington, Dept Med, Seattle, WA 98195 USA