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Accuracy of GFR estimating equations in a large Swedish cohort : implications for radiologists in daily routine and research

Nyman, Ulf LU ; Grubb, Anders LU ; Lindström, Veronica LU and Björk, Jonas LU (2017) In Acta radiologica (Stockholm, Sweden : 1987) 58(3). p.367-375
Abstract

BACKGROUND: Guidelines recommend estimation of glomerular filtration rate (eGFR) prior to iodine contrast media (CM) examinations. It is also recommended that absolute eGFR in mL/min, not commonly used relative GFR (adjusted to body surface area; mL/min/1.73 m(2)), should be preferred when dosing and evaluating toxicity of renally excreted drugs.

PURPOSE: To validate the absolute Lund-Malmö equation (LM-ABS) in comparison with the absolute Cockcroft-Gault (CG) equation and the relative equations, revised Lund-Malmö (LM-REV), MDRD, and CKD-EPI, after converting relative estimates to absolute values, and to analyze change in eGFR classification when absolute instead of relative eGFR was used.

MATERIAL AND METHODS: A total of... (More)

BACKGROUND: Guidelines recommend estimation of glomerular filtration rate (eGFR) prior to iodine contrast media (CM) examinations. It is also recommended that absolute eGFR in mL/min, not commonly used relative GFR (adjusted to body surface area; mL/min/1.73 m(2)), should be preferred when dosing and evaluating toxicity of renally excreted drugs.

PURPOSE: To validate the absolute Lund-Malmö equation (LM-ABS) in comparison with the absolute Cockcroft-Gault (CG) equation and the relative equations, revised Lund-Malmö (LM-REV), MDRD, and CKD-EPI, after converting relative estimates to absolute values, and to analyze change in eGFR classification when absolute instead of relative eGFR was used.

MATERIAL AND METHODS: A total of 3495 plasma clearance of iohexol to measure GFR (mGFR) served as reference test. Bias, precision, and accuracy (percentage of estimates ±30% of mGFR; P30) were compared overall and after stratification for various mGFR, eGFR, age, and BMI subgroups.

RESULTS: The overall P30 results of CG/LM-ABS/LM-REV/MDRD/CKD-EPI were 62.8%/84.9%/83.7%/75.3%/75.6%, respectively. LM-ABS was the most stable equations across subgroups and the only equation that did not exhibit marked overestimation in underweight patients. For patients with relative eGFR 30-44 and 45-59 mL/min/1.73 m(2), 36% and 58% of men, respectively, and 24% and 32% of women, respectively, will have absolute eGFR values outside these relative eGFR intervals.

CONCLUSION: Choosing one equation to estimate GFR prior to contrast medium examinations, LM-ABS may be preferable. Unless absolute instead of relative eGFR are used, systematic inaccuracies in assessment of renal function may occur in daily routine and research on CM nephrotoxicity may be flawed.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta radiologica (Stockholm, Sweden : 1987)
volume
58
issue
3
pages
367 - 375
publisher
John Wiley & Sons
external identifiers
  • scopus:85011587046
  • wos:000394268900017
ISSN
1600-0455
DOI
10.1177/0284185116646143
language
English
LU publication?
yes
id
eb5b8cfe-59ff-4637-89b7-86654a27501c
date added to LUP
2016-11-22 18:56:31
date last changed
2018-10-28 11:49:10
@article{eb5b8cfe-59ff-4637-89b7-86654a27501c,
  abstract     = {<p>BACKGROUND: Guidelines recommend estimation of glomerular filtration rate (eGFR) prior to iodine contrast media (CM) examinations. It is also recommended that absolute eGFR in mL/min, not commonly used relative GFR (adjusted to body surface area; mL/min/1.73 m(2)), should be preferred when dosing and evaluating toxicity of renally excreted drugs.</p><p>PURPOSE: To validate the absolute Lund-Malmö equation (LM-ABS) in comparison with the absolute Cockcroft-Gault (CG) equation and the relative equations, revised Lund-Malmö (LM-REV), MDRD, and CKD-EPI, after converting relative estimates to absolute values, and to analyze change in eGFR classification when absolute instead of relative eGFR was used.</p><p>MATERIAL AND METHODS: A total of 3495 plasma clearance of iohexol to measure GFR (mGFR) served as reference test. Bias, precision, and accuracy (percentage of estimates ±30% of mGFR; P30) were compared overall and after stratification for various mGFR, eGFR, age, and BMI subgroups.</p><p>RESULTS: The overall P30 results of CG/LM-ABS/LM-REV/MDRD/CKD-EPI were 62.8%/84.9%/83.7%/75.3%/75.6%, respectively. LM-ABS was the most stable equations across subgroups and the only equation that did not exhibit marked overestimation in underweight patients. For patients with relative eGFR 30-44 and 45-59 mL/min/1.73 m(2), 36% and 58% of men, respectively, and 24% and 32% of women, respectively, will have absolute eGFR values outside these relative eGFR intervals.</p><p>CONCLUSION: Choosing one equation to estimate GFR prior to contrast medium examinations, LM-ABS may be preferable. Unless absolute instead of relative eGFR are used, systematic inaccuracies in assessment of renal function may occur in daily routine and research on CM nephrotoxicity may be flawed.</p>},
  author       = {Nyman, Ulf and Grubb, Anders and Lindström, Veronica and Björk, Jonas},
  issn         = {1600-0455},
  language     = {eng},
  number       = {3},
  pages        = {367--375},
  publisher    = {John Wiley & Sons},
  series       = {Acta radiologica (Stockholm, Sweden : 1987)},
  title        = {Accuracy of GFR estimating equations in a large Swedish cohort : implications for radiologists in daily routine and research},
  url          = {http://dx.doi.org/10.1177/0284185116646143},
  volume       = {58},
  year         = {2017},
}