PURPOSE: To test various ways of combining creatinine and cystatin C in equations to predict glomerular filtration rate (GFR). MATERIAL AND METHODS: Performance of the following expressions to predict GFR was compared with measured GFR (iohexol clearance, mL/min/1.73 m(2)) in 857 patients: (i) Lund-Malmö creatinine equation, (ii) Grubb cystatin C equation, (iii) arithmetic mean of (1) and (2), (iv) geometric mean of (1) and (2), (v) linear regression on (1) and (2), (vi) regression on (1) and cystatin C, and (vii) regression on creatinine, cystatin C, age and gender. RESULTS: For the entire cohort median percent error (bias) was <5% for all expressions, though all expressions tended to underestimate (-8.3 to 15.8%) GFR at levels > or =90 mL/min/1.73 m(2). The five expressions combining creatinine and cystatin C significantly improved correlation and accuracy (p<0.001) within 15 and 30% of measured GFR compared with the equations based on the separate analytes and with no significant difference between the five expressions. In a subgroup of patients with neurological disease and muscle atrophy the cystatin C equation performed better than the expressions combining creatinine and cystatin C. CONCLUSION: Simply calculating the arithmetic mean of predicted GFR based on separate creatinine and cystatin C equations performs equally well as more complex equations. Reporting GFR based on separate creatinine and cystatin C equations, and their arithmetic mean also has the definite advantage that the physician can choose the estimated GFR, most appropriate depending on the clinical setting and patient characteristics.
PURPOSE: To test various ways of combining creatinine and cystatin C in equations to predict glomerular filtration rate (GFR). MATERIAL AND METHODS: Performance of the following expressions to predict GFR was compared with measured GFR (iohexol clearance, mL/min/1.73 m(2)) in 857 patients: (i) Lund-Malmö creatinine equation, (ii) Grubb cystatin C equation, (iii) arithmetic mean of (1) and (2), (iv) geometric mean of (1) and (2), (v) linear regression on (1) and (2), (vi) regression on (1) and cystatin C, and (vii) regression on creatinine, cystatin C, age and gender. RESULTS: For the entire cohort median percent error (bias) was <5% for all expressions, though all expressions tended to underestimate (-8.3 to 15.8%) GFR at levels > or =90 mL/min/1.73 m(2). The five expressions combining creatinine and cystatin C significantly improved correlation and accuracy (p<0.001) within 15 and 30% of measured GFR compared with the equations based on the separate analytes and with no significant difference between the five expressions. In a subgroup of patients with neurological disease and muscle atrophy the cystatin C equation performed better than the expressions combining creatinine and cystatin C. CONCLUSION: Simply calculating the arithmetic mean of predicted GFR based on separate creatinine and cystatin C equations performs equally well as more complex equations. Reporting GFR based on separate creatinine and cystatin C equations, and their arithmetic mean also has the definite advantage that the physician can choose the estimated GFR, most appropriate depending on the clinical setting and patient characteristics.
Authors: Václav Ptáčník; David Zogala; Daniela Skibová; Hana Jiskrová; Jiří Trnka; Vladimír Tesař; Romana Ryšavá; Martin Šámal Journal: Eur Radiol Date: 2018-11-09 Impact factor: 5.315
Authors: George J Schwartz; Christopher Cox; Jesse C Seegmiller; Paula S Maier; Donna DiManno; Sue L Furth; Bradley A Warady; Alvaro Munoz Journal: Pediatr Nephrol Date: 2019-11-03 Impact factor: 3.714
Authors: Emil den Bakker; Reinoud Gemke; Joanna A E van Wijk; Isabelle Hubeek; Birgit Stoffel-Wagner; Arend Bökenkamp Journal: Pediatr Nephrol Date: 2018-05-17 Impact factor: 3.714