[1] Univ Edinburgh, Sch Hlth Social Sci, Edinburgh EH8 9AG, Midlothian, Scotland
[2] Harvard Univ, Brigham & Womens Hosp, Sch Med, Dept Med, Boston, MA 02115 USA
[3] Harvard Univ, Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA 02115 USA
[4] Univ Edinburgh, Inst Study Sci Technol & Innovat, Edinburgh, Midlothian, Scotland
[5] Univ Edinburgh, Ctr Populat Hlth Sci, EHlth Res Grp, Edinburgh, Midlothian, Scotland
[6] Univ Birmingham, Sch Clin & Expt Med, Edgbaston, England
[7] Harvard Univ, Brigham & Womens Hosp, Sch Med, Div Gen Internal Med & Primary Care, Boston, MA 02115 USA