This document was published more than 2 years ago. The nature of the evidence may have changed.
Accurate estimates of kidney function are essential for appropriate treatment decisions. The best measure of kidney function is the glomerular filtration rate (GFR). To measure GFR is complicated in clinical practice, requiring substantial time and resources. Alternatively, GFR can be estimated from a blood sample by using equations (eGFR) based on the plasma concentration of creatinine or cystatin C. Creatinine is formed in muscles as a break-down product of creatine, while cystatin C is a small protein produced by nearly all cells in the body.
Is it uncertain which biomarkers and equations yield the most accurate estimates of GFR, and opinions and practices vary. The cost-effectiveness of various methods has also been questioned. This report aims to review how accurately the different equations based on creatinine, cystatin C, or a combination of both markers, can estimate GFR in different patient groups. We have not evaluated either the direct benefits to patients’ health or the levels of accuracy required in different clinical situations.
* In usual practice, an eGFR equation is defined as having sufficient accuracy when at least 75% of the estimates fall within ±30% of the measured GFR.
** IDMS = Isotope dilution mass spectrometry, an internationally certified standard for plasma creatinine analysis.
How to cite this report: SBU. Methods to estimate and measure renal function (glomerular filtration rate). Stockholm: Swedish Council on Health Technology Assessment (SBU); 2012. SBU report no 214 (in Swedish).
presents a comprehensive, systematic assessment of available scientific evidence. The certainty of the evidence for each finding is systematically reviewed and graded. Full assessments include economic, social, and ethical impact analyses.
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