[1] Grp Hlth Cooperat Puget Sound, Seattle, WA USA
[2] Grp Hlth Res Inst, Seattle, WA 98101 USA
[3] Univ Washington, Sch Publ Hlth, Dept Epidemiol, Seattle, WA 98195 USA
[4] Fred Hutchinson Canc Ctr, Seattle, WA USA
[5] Univ Texas Houston, Ctr Hlth Promot & Prevent Res, Sch Publ Hlth, Houston, TX USA
[6] Kaiser Permanente Northwest, Ctr Hlth Res, Portland, OR USA