title: Comparison of the performance of the updated Schwartz, combined Schwartz and the Grubb glomerular filtration rate equations in a general pediatric population.
abstract: To determine the performance of the updated Schwartz, combined Schwartz and Grubb glomerular filtration rate (GFR) equations in a relatively large number of healthy children with no known renal disease, we studied 712 students aged between seven and 18 years from the Isfahan province of Iran by random cluster sampling between 2009 and 2010. Blood investigations included blood urea nitrogen, creatinine and cystatin C. For each participant, GFR was calculated based on the three equations. We used Bland-Altman plots and weighted kappa statistics to compare the performance of the study equations. The mean age of the children was 12.2 ± 2.4 years. A high concordance in estimating GFR (mean difference: 0 ± 12.7 mL/min/1.73 m 2 ) and a very good agreement in defining chronic kidney disease (CKD) and non-CKD individuals (weighted kappa: 0.85; 95% confidence intervals: 0.69-1) were observed between the updated Schwartz and the combined Schwartz equations. Poor agreement was observed between the Grubb equation and two Schwartz equations in estimating GFR and defining CKD. There was no systematic deviation between the updated Schwartz and the combined Schwartz equations in children with normal renal function. The Grubb equation was highly inconsistent with both Schwartz equations in this population. We conclude that the updated Schwartz equation is simpler and more accessible than the combined Schwartz equation in daily clinical practice and CKD screening programs.
authors.forename: Alaleh
authors.initials: A
authors.lastname: Gheissari
authors.affiliation: Isfahan Kidney Diseases Research Center; Medical Students Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Peyman
authors.initials: P
authors.lastname: Roomizadeh
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
authors.forename: Amin
authors.initials: A
authors.lastname: Abedini
authors.forename: Shaghayegh
authors.initials: S
authors.lastname: Haghjooy-Javanmard
authors.forename: Seyed-Hossein
authors.initials: SH
authors.lastname: Abtahi
authors.forename: Bahareh
authors.initials: B
authors.lastname: Mehdikhani
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D002648:Child; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005919:Glomerular Filtration Rate; D006801:Humans; D007492:Iran / Q000453:epidemiology; D007668:Kidney / Q000503:physiopathology*; D008954:Models, Biological; D011237:Predictive Value of Tests; D012016:Reference Values; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D003404:Creatinine