[1] Oregon Hlth & Sci Univ, Dept Family Med, Portland, OR 97239 USA
[2] Oregon Hlth & Sci Univ, Dept Publ Hlth & Prevent Med, Portland, OR 97201 USA
[3] Oregon Hlth & Sci Univ, Sch Nursing, Portland, OR 97239 USA
[4] Oregon Hlth & Sci Univ, Knight Canc Inst Biostat Shared Resource, Portland, OR 97239 USA
[5] Asian Hlth & Serv Ctr, Portland, OR USA
[6] Oregon Hlth & Sci Univ, Dept Med, Div Gastroenterol, Portland, OR 97239 USA