Measuring GFR: A Systematic Review

• Published in: American journal of kidney diseases Vol. 64; no. 3; pp. 411 - 424
• Main Authors: Soveri, Inga, MD, PhD, Berg, Ulla B., MD, PhD, Björk, Jonas, PhD, Elinder, Carl-Gustaf, MD, PhD, Grubb, Anders, MD, PhD, Mejare, Ingegerd, PhD, Sterner, Gunnar, MD, PhD, Bäck, Sten-Erik, MSc, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 2014; Elsevier
• Subjects: accuracy; Biological and medical sciences; clearance marker; Clinical Medicine; Cross-Sectional Studies; Glomerular Filtration Rate; Glomerular filtration rate (GFR); glomerular filtration rate (GFR) measurement; Humans; Kidney Function Tests - methods; Klinisk medicin; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Nephrology; Nephrology. Urinary tract diseases; renal function; Reproducibility of Results; Urologi och njurmedicin; Urology and Nephrology; glomerular filtration rate (GFR) measurement; renal function; accuracy; Glomerular filtration rate (GFR); clearance marker; Nephrology; Renal function; Biological marker; Biological indicator; Review; Clearance; Urology; Glomerular filtration rate; Accuracy; Bibliographic review; Quantitative analysis
• ISSN: 0272-6386; 1523-6838; 1523-6838
• DOI: 10.1053/j.ajkd.2014.04.010

Background No comprehensive systematic review of the accuracy of glomerular filtration rate (GFR) measurement methods using renal inulin clearance as reference has been published. Study Design Systematic review with meta-analysis of cross-sectional diagnostic studies. Setting & Population Published original studies and systematic reviews in any population. Selection Criteria for Studies Index and reference measurements conducted within 48 hours; at least 15 participants studied; GFR markers measured in plasma or urine; plasma clearance calculation algorithm verified in another study; tubular secretion of creatinine had not been blocked by medicines. Index Tests Endogenous creatinine clearance; renal or plasma clearance of chromium 51−labeled ethylenediaminetetraacetic acid (51 Cr-EDTA), diethylenetriaminepentaacetic acid (DTPA), iohexol, and iothalamate; and plasma clearance of inulin. Reference Test Renal inulin clearance measured under continuous inulin infusion and urine collection. Results Mean bias < 10%, median bias < 5%, the proportion of errors in the index measurements that did not exceed 30% (P30 ) ≥ 80%, and P10 ≥ 50% were set as requirements for sufficient accuracy. Based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach, the quality of evidence across studies was rated for each index method. Renal clearance of iothalamate measured GFR with sufficient accuracy (strong evidence). Renal and plasma clearance of51 Cr-EDTA and plasma clearance of iohexol were sufficiently accurate to measure GFR (moderately strong evidence). Renal clearance of DTPA, renal clearance of iohexol, and plasma clearance of inulin had sufficient accuracy (limited evidence). Endogenous creatinine clearance was an inaccurate method (strong evidence), as was plasma clearance of DTPA (limited evidence). The evidence to determine the accuracy of plasma iothalamate clearance was insufficient. With the exception of plasma clearance of inulin, only renal clearance methods had P30 > 90%. Limitations The included studies were few and most were old and small, which may limit generalizability. Requirements for sufficient accuracy may depend on clinical setting. Conclusions At least moderately strong evidence suggests that renal clearance of51 Cr-EDTA or iothalamate and plasma clearance of51 Cr-EDTA or iohexol are sufficiently accurate methods to measure GFR.