1 National Health and Medical Research Council (NHMRC) Clinical Trials Centre, University of Sydney, Sydney, Australia.
2 New South Wales Health Pathology Department of Chemical Pathology, Prince of Wales Hospital and School of Medical Sciences, University of New South Wales, Sydney, Australia.
3 School of Public Health, University of Sydney, Sydney, Australia.
4 Department of Clinical Biochemistry, The Christie NHS Foundation Trust, Manchester, UK.
5 Division of Cancer Sciences, The University of Manchester, Manchester, UK.
6 The Norwegian Quality Improvement of Primary Care Laboratories (NOKLUS), Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway.
7 Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway.
8 Department of Clinical Epidemiology, Biostatistics & Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.