1. University of Oxford; Nuffield Department of Primary Care Health Sciences; Oxford UK
2. Bond University; Centre for Research in Evidence-Based Practice (CREBP); University Drive Gold Coast Queensland Australia 4229
3. University of Oxford; Bodleian Health Care Libraries; Knowledge Centre, ORC Research Building, Old Road Campus Oxford Oxfordshire UK OX3 7DQ
4. University of Oxford; Cancer Epidemiology Unit, Nuffield Department of Population Health; Richard doll Bldg Old Road Campus, Roosevelt Driver Oxford UK OX3 7LF