title: Improved glomerular filtration rate estimation by an artificial neural network.
abstract: BACKGROUND
  Accurate evaluation of glomerular filtration rates (GFRs) is of critical importance in clinical practice. A previous study showed that models based on artificial neural networks (ANNs) could achieve a better performance than traditional equations. However, large-sample cross-sectional surveys have not resolved questions about ANN performance.
  
  
  METHODS
  A total of 1,180 patients that had chronic kidney disease (CKD) were enrolled in the development data set, the internal validation data set and the external validation data set. Additional 222 patients that were admitted to two independent institutions were externally validated. Several ANNs were constructed and finally a Back Propagation network optimized by a genetic algorithm (GABP network) was chosen as a superior model, which included six input variables; i.e., serum creatinine, serum urea nitrogen, age, height, weight and gender, and estimated GFR as the one output variable. Performance was then compared with the Cockcroft-Gault equation, the MDRD equations and the CKD-EPI equation.
  
  
  RESULTS
  In the external validation data set, Bland-Altman analysis demonstrated that the precision of the six-variable GABP network was the highest among all of the estimation models; i.e., 46.7 ml/min/1.73 m(2) vs. a range from 71.3 to 101.7 ml/min/1.73 m(2), allowing improvement in accuracy (15% accuracy, 49.0%; 30% accuracy, 75.1%; 50% accuracy, 90.5% [P<0.001 for all]) and CKD stage classification (misclassification rate of CKD stage, 32.4% vs. a range from 47.3% to 53.3% [P<0.001 for all]). Furthermore, in the additional external validation data set, precision and accuracy were improved by the six-variable GABP network.
  
  
  CONCLUSIONS
  A new ANN model (the six-variable GABP network) for CKD patients was developed that could provide a simple, more accurate and reliable means for the estimation of GFR and stage of CKD than traditional equations. Further validations are needed to assess the ability of the ANN model in diverse populations.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Pei
authors.forename: Ningshan
authors.initials: N
authors.lastname: Li
authors.forename: Yunong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.forename: Jinxia
authors.initials: J
authors.lastname: Chen
authors.forename: Linsheng
authors.initials: L
authors.lastname: Lv
authors.forename: Huijuan
authors.initials: H
authors.lastname: Ma
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wu
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhao
authors.forename: Tanqi
authors.initials: T
authors.lastname: Lou
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016571:Neural Networks, Computer; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000503:physiopathology*; D015203:Reproducibility of Results