[1] SUNY Buffalo, Social & Prevent Med, Buffalo, NY USA
[2] Univ Wisconsin, Dept Ophthalmol & Visual Sci, Madison, WI USA
[3] Kaiser Permanente NW, Ctr Hlth Res, Portland, OR USA
[4] Univ Iowa, Dept Epidemiol, Iowa City, IA USA
[5] Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA
[6] Case Western Reserve Univ, Dept Epidemiol & Biostat, Cleveland, OH 44106 USA