1. Birmingham Quality (UK NEQAS), University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
2. Clinical Chemistry, Royal Cornwall Hospital, Truro, UK
3. Clinical Biochemistry, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, UK
4. Sheffield Kidney Institute, Northern General Hospital, Sheffield, UK
5. Centre for Kidney Research and Innovation, Academic Unit for Translational Medical Sciences, School of Medicine (Royal Derby Hospital Campus), University of Nottingham, UK
6. Renal Unit, South Tees Hospitals NHS Foundation Trust, Middlesbrough, UK
7. UK Renal Registry, Bristol UK
8. Clinical Biochemistry, Royal Preston Hospital, Preston, UK