[1] Calif Pacific Med Ctr, Res Inst, San Francisco, CA USA
[2] Optasia Med, Cheadle, Cheshire, England
[3] Univ Minnesota, Div Hlth Policy & Management, Pk Nicollet Inst Res & Educ, Minneapolis, MN 55455 USA
[4] Univ Calif San Francisco, San Francisco, CA 94143 USA
[5] Oregon Hlth & Sci Univ, Portland, OR 97201 USA
[6] Univ Calif San Diego, San Diego, CA 92103 USA
[7] Univ Minnesota, Minneapolis, MN 55455 USA
[8] Minneapolis VA Hlth Syst, Minneapolis, MN USA