1. University of Oxford; Nuffield Department of Primary Care Health Sciences; Woodstock Road Oxford Oxon UK OX2 6GG
2. University of Oxford; Bodleian Health Care Libraries; Knowledge Centre, ORC Research Building, Old Road Campus Oxford Oxfordshire UK OX3 7DQ
3. Bond University; Centre for Research in Evidence-Based Practice (CREBP); Gold Coast Queensland Australia
4. Center for General Practice at Aalborg University; Fyrkildevej 7 Aalborg Denmark 9220