[1] Univ Newcastle, Fac Hlth & Med, Sch Med & Publ Hlth, Callaghan, NSW 2308, Australia
[2] Univ Newcastle, Hunter Med Res Inst, New Lambton, NSW 2305, Australia
[3] John Hunter Hosp, Dept Gen Med, New Lambton Hts, NSW 2305, Australia
[4] John Hunter Hosp, Dept Traumatol, New Lambton Hts, NSW 2305, Australia
[5] Liverpool Hosp, Ingham Inst Appl Med Res, Whitlam Orthopaed Res Ctr, Liverpool, NSW 2170, England
[6] Univ New South Wales, Fac Med, South Western Sydney Clin Sch, Liverpool, Merseyside 2170, Australia
[7] Cent Queensland Univ, Sch Human Hlth & Social Sci, Brisbane, Qld 4000, Australia
[8] Monash Univ, Ctr Med Use & Safety, Melbourne, Vic 3052, Australia
[9] Hunter New England Populat Hlth, Wallsend, Tyne & Wear 2287, Australia