Accuracy of glomerular filtration rate estimation using creatinine and cystatin C for identifying and monitoring moderate chronic kidney disease: the eGFR-C study.

Background: Estimation of glomerular filtration rate using equations based on creatinine is widely used to manage chronic kidney disease. In the UK, the Chronic Kidney Disease Epidemiology Collaboration creatinine equation is recommended. Other published equations using cystatin C, an alternative marker of kidney function, have not gained widespread clinical acceptance.

Biological variation of measured and estimated glomerular filtration rate in patients with chronic kidney disease.

When assessing changes in glomerular filtration rate (GFR) it is important to differentiate pathological change from intrinsic biological and analytical variation. GFR is measured using complex reference methods (e.g.