1. University of Göttingen; Department of General Practice/Family Medicine; Humboldtalle 38 Göttingen Lower Saxony Germany 37073
2. University of Dundee; Centre for Primary Care and Population Research, Division of Clinical and Population Sciences and Education; Mackenzie Buildiing Kirsty Semple Way Dundee Tayside, Scotland UK DD2 4BF
3. Frontier Science (Scotland) Ltd; Grampian View Kincraig, Kingussie Inverness-shire UK PH21 1NA
4. University of Edinburgh; School of Clinical Sciences; Old College South Bridge Edinburgh Lothian UK EH8 9YL
5. North York General Hospital, University of Toronto; Department of Family and Community Medicine; 500 University Avenue, 5th Floor Toronto ON Canada M5G 1V7