[1] Univ Exeter, Med Sch Primary Care, Exeter, Devon, England
[2] Univ Cambridge, Inst Publ Hlth, Cambridge Ctr Hlth Serv Res, Cambridge, England
[3] Univ Cambridge, Sch Primary Care Res, Cambridge, England
[4] Publ Hlth England, Natl Canc Registrat & Anal Serv, London, England
[5] UCL, Dept Behav Sci & Hlth, Epidemiol Canc Healthcare & Outcomes ECHO Grp, Canc Epidemiol, London, England