[1] Dartmouth Coll, Geisel Sch Med, Dartmouth Inst Hlth Policy & Clin Practice, Lebanon, NH USA
[2] Univ Calif San Francisco, Dept Family & Community Med, 3333 Calif St,Suite 465, San Francisco, CA 94118 USA
[3] Univ Calif San Francisco, Philip R Lee Inst Hlth Policy Studies, San Francisco, CA 94143 USA
[4] Univ Warwick, Warwick Med Sch, Div Hlth Sci, Coventry, W Midlands, England
[5] Hlth Fdn, 8 Salisbury Sq, London, England
[6] Dartmouth Hitchcock Hlth, Lebanon, NH USA
[7] Natl Bur Econ Res, Cambridge, MA 02138 USA
[8] Harvard Univ, Dept Hlth Policy & Management, Harvard TH Chan Sch Publ Hlth, Boston, MA USA