Niels Jonker1, Berna Aslan2, Beatriz Boned3,4, Fernando Marqués-García3,5, Carmen Ricós3, Virtudes Alvarez3, William Bartlett6, Federica Braga7, Anna Carobene8, Abdurrahman Coskun9, Jorge Diaz-Garzón3,10, Pilar Fernández-Calle3,10, Elisabet Gonzalez-Lao3,11, Joana Minchinela3,12, Carmen Perich3, Margarita Simón3,13, Sverre Sandberg14,15,16, Aasne K Aarsand14,15. 1. Certe-Wilhelmina Ziekenhuis Assen, Assen, The Netherlands. 2. Institute for Quality Management in Healthcare (IQMH), Centre for Proficiency Testing, Toronto, Ontario, Canada. 3. Spanish Society of Laboratory Medicine (SEQCML), Analytical Quality Commission, Barcelona, Spain. 4. Royo Villanova Hospital, Zaragoza, Spain. 5. Department of Clinical Biochemistry, University Hospital of Salamanca, Salamanca, Spain. 6. School of Medicine, University of Dundee, Dundee, Scotland, UK. 7. Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan, Milan, Italy. 8. Servizio Medicina di Laboratorio, Ospedale San Raffaele, Milan, Italy. 9. Acibadem Mehmet Ali Aydınlar University, School of Medicine, Atasehir, Istanbul, Turkey. 10. Department of Laboratory Medicine, La Paz University Hospital, Madrid, Spain. 11. Quality Healthcare Consulting, Grupo ACMS, Madrid, Spain. 12. Metropolitana Nord Unified Laboratory (LUMN), Germans Trias i Pujol University Hospital, Badalona, Spain. 13. Consortium of Laboratory Intercomarcal Alt Penedès and Garraf l'Anoia, Vilafranca del Penedès, Spain. 14. Norwegian Porphyria Centre, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway. 15. Norwegian Organization for Quality Improvement of Laboratory Examinations (NOKLUS), Haraldsplass Deaconess Hospital, Bergen, Norway. 16. Department of Global Health and Primary Care, Faculty of Medicine, University of Bergen, Bergen, Norway.
Abstract
OBJECTIVES: Kidney markers are some of the most frequently used laboratory tests in patient care, and correct clinical decision making depends upon knowledge and correct application of biological variation (BV) data. The aim of this study was to review available BV data and to provide updated BV estimates for the following kidney markers in serum and plasma; albumin, creatinine, cystatin C, chloride, potassium, sodium and urea. CONTENT: Relevant studies were identified from a historical BV database as well as by systematic literature searches. Retrieved publications were appraised by the Biological Variation Data Critical Appraisal Checklist (BIVAC). Meta-analyses of BIVAC compliant studies with similar design were performed to deliver global estimates of within-subject (CVI) and between-subject (CVG) BV estimates. Out of the 61 identified papers, three received a BIVAC grade A, four grade B, 48 grade C, five grade D grade and one was not appraised as it did not report numerical BV estimates. Most studies were identified for creatinine (n=48). BV estimates derived from the meta-analysis were in general lower than previously reported estimates for all analytes except urea. For some measurands, BV estimates may be influenced by age or states of health, but further data are required. SUMMARY: This review provides updated global BV estimates for kidney related measurands. For all measurands except for urea, these estimates were lower than previously reported. OUTLOOK: For the measurands analyzed in this review, there are sufficient well-designed studies available to publish a trustworthy estimate of BV. However, for a number of newly appearing kidney markers no suitable data is available and additional studies are required.
OBJECTIVES: Kidney markers are some of the most frequently used laboratory tests in patient care, and correct clinical decision making depends upon knowledge and correct application of biological variation (BV) data. The aim of this study was to review available BV data and to provide updated BV estimates for the following kidney markers in serum and plasma; albumin, creatinine, cystatin C, chloride, potassium, sodium and urea. CONTENT: Relevant studies were identified from a historical BV database as well as by systematic literature searches. Retrieved publications were appraised by the Biological Variation Data Critical Appraisal Checklist (BIVAC). Meta-analyses of BIVAC compliant studies with similar design were performed to deliver global estimates of within-subject (CVI) and between-subject (CVG) BV estimates. Out of the 61 identified papers, three received a BIVAC grade A, four grade B, 48 grade C, five grade D grade and one was not appraised as it did not report numerical BV estimates. Most studies were identified for creatinine (n=48). BV estimates derived from the meta-analysis were in general lower than previously reported estimates for all analytes except urea. For some measurands, BV estimates may be influenced by age or states of health, but further data are required. SUMMARY: This review provides updated global BV estimates for kidney related measurands. For all measurands except for urea, these estimates were lower than previously reported. OUTLOOK: For the measurands analyzed in this review, there are sufficient well-designed studies available to publish a trustworthy estimate of BV. However, for a number of newly appearing kidney markers no suitable data is available and additional studies are required.