[1] Dartmouth Coll, Dartmouth Inst Hlth Policy & Clin Practice, Hanover, NH 03755 USA
[2] Univ Hertfordshire, Dept Psychol, Hatfield AL10 9AB, Herts, England
[3] Informed Med Decis Fdn, Boston, MA USA
[4] Harvard Univ, Sch Publ Hlth, Boston, MA 02115 USA
[5] Boston Univ, Sch Law, Boston, MA 02215 USA
[6] Cardiff Univ, Support Unit Res Evidence, Cardiff, Wales
[7] Dartmouth Ctr Hlth Care Delivery Sci, Hanover, NH USA