1 Department of Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom. Electronic address: elamb@nhs.net.
2 Test Evaluation Research Group, University of Birmingham, Birmingham, United Kingdom; NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom.
3 University Hospitals of Leicester, Birmingham, United Kingdom.
4 Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom.
5 Renal Medicine, Queen Elizabeth Hospital Birmingham, University of Birmingham, Birmingham, United Kingdom.
6 Evelina London Children's Hospital, London, United Kingdom.
7 Test Evaluation Research Group, University of Birmingham, Birmingham, United Kingdom; NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom; Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom.
8 Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom.
9 Centre for Health Services Studies, University of Kent, Canterbury, United Kingdom.
10 Salford Royal NHS Foundation Trust, Salford, United Kingdom.
11 University of Leicester, Leicester, United Kingdom.
12 Kidney Care UK, Alton, United Kingdom.
13 King's College London & King's College Hospital NHS Foundation Trust, London, United Kingdom.
14 Leeds Institute of Health Sciences, University of Leeds, Leeds, United Kingdom.
15 Royal Derby Hospital, Derby, United Kingdom.
16 Department of Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom.