[1] Univ Cambridge, Dept Publ Hlth & Primary Care, Cambridge CB2 1TN, England
[2] Univ Durham, Sch Med Pharm & Hlth, Durham DH1 3HP, England
[3] Univ Bristol, Sch Social & Community Med, Bristol BS8 1TH, Avon, England
[4] Univ Western Australia, Sch Primary Aboriginal & Rural Hlth Care, Nedlands, WA 6009, Australia
[5] Univ Melbourne, Gen Practice & Primary Care Acad Ctr, Melbourne, Vic 3010, Australia