[1] Univ Cambridge, Dept Publ Hlth & Primary Care, Primary Care Unit, Cambridge, England
[2] Univ Melbourne, Dept Gen Practice, Primary Care Canc Res, Carlton, Vic, Australia
[3] Univ Durham, Sch Med Pharm & Hlth, Evaluat Res Dev Unit, Bristol, Avon, England
[4] Univ Bristol, Sch Social & Community Med, Ctr Acad Primary Care, Bristol, Avon, England
[5] Univ Exeter, Dept Primary Care Diagnost, Coll House,St Lukes Campus, Exeter, Devon, England