[1] Univ Durham, Sch Med Pharm & Hlth, Stockton On Tees TS17 6BH, England
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Gen Practice, Groningen, Netherlands
[3] Airedale Natl Hlth Serv Fdn Trust, Keighley, England
[4] Univ Bristol, Sch Clin Sci, Bristol, Avon, England
[5] Ontario Inst Canc Res, Toronto, ON, Canada
[6] Univ Melbourne, Dept Gen Practice, Melbourne, Vic, Australia
[7] Royal Coll Surgeons Ireland, Dublin 2, Ireland
[8] Univ Ferrara, Dept Biomed & Specialty Surg Sci, I-44100 Ferrara, Italy
[9] Univ Toronto, Inst Hlth Policy Management & Evaluat, Toronto, ON, Canada
[10] Univ Toronto, Fac Med, Toronto, ON, Canada
[11] Univ Toronto, Dept Paediat, Toronto, ON M5S 1A1, Canada
[12] Univ Toronto, Dept Med, Div Med Oncol & Haematol, Toronto, ON, Canada
[13] Univ Exeter, Sch Med, Exeter, Devon, England
[14] Canc Res UK, London, England
[15] UCL, Dept Epidemiol & Publ Hlth, London, England
[16] UCL, Res Dept Oncol, London, England
[17] Univ Hull, Hull York Med Sch, Kingston Upon Hull HU6 7RX, N Humberside, England
[18] Kings Coll London, Fac Life Sci & Med, London, England
[19] Univ Queensland, Fac Med & Biomed Sci, Brisbane, Qld, Australia
[20] Bangor Univ, North Wales Ctr Primary Care Res, Bangor, Wales
[21] Glenfield Hosp, Leicester, Leics, England
[22] Univ Cambridge, Dept Publ Hlth & Primary Care, Cambridge, England
[23] Charles Univ Prague, Dept Gen Practice, Prague, Czech Republic
[24] Univ Manitoba, Dept Family Med, Winnipeg, MB, Canada
[25] Juravinski Canc Ctr, Hamilton, ON, Canada
[26] NCI, Div Canc Control & Populat Sci, Bethesda, MD 20892 USA
[27] Aarhus Univ, Dept Publ Hlth, Aarhus, Denmark
[28] Oxford Brookes Univ, Dept Clin Hlth Care, Oxford OX3 0BP, England
[29] Univ Edinburgh, Ctr Populat Hlth Sci, Edinburgh, Midlothian, Scotland
[30] Amer Canc Soc, Atlanta, GA 30329 USA
[31] Univ Med Ctr Utrecht, Dept Gen Practice, Utrecht, Netherlands