[1] Univ Aberdeen, Dept Gen Practice & Primary Care, Aberdeen AB9 1FX, Scotland
[2] Birmingham Heartlands Hosp, Dept Resp Med, Birmingham B9 5ST, W Midlands, England
[3] Univ Southampton, Primary Med Care Grp, Southampton SO9 5NH, Hants, England
[4] Oxfordshire Hlth Author, Oxford OX3 9DZ, England
[5] Univ Sheffield, Sch Med, Div Mol & Genet Med, Sheffield, S Yorkshire, England
[6] Queens Med Ctr, PHLS Antimicrobial Susceptibil Surveillance Unit, Nottingham NG7 2UH, England
[7] M TAG Ltd, London, England
[8] Univ Newcastle, Ctr Clin Epidemiol & Biostat, Newcastle, NSW 2308, Australia
[9] Univ Sydney, Fac Hlth Sci, Sydney, NSW 2006, Australia