Jill J Francis1
, Alan Tinmouth2,3
, Simon J Stanworth4
, Jeremy M Grimshaw2
, Marie Johnston5
, Chris Hyde4
, Charlotte Stockton6
, Jamie C Brehaut7
, Dean Fergusson2
and Martin P Eccles8 
1
Health Services Research Unit, University of Aberdeen, UK
2
Clinical Epidemiology Programme, Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa, Canada
3
Canadian Blood Services, Ottawa, Canada
4
NHS Blood & Transplant, John Radcliffe Hospital, Headington, Oxford, UK
5
Department of Psychology, University of Aberdeen, UK
6
Centre for Medical Statistics and Health Evaluation, University of Liverpool, UK
7
Clinical Epidemiology Programme, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Canada
8
Institute of Health and Society, Newcastle University, UK