title: A systematic review of single-sample glomerular filtration rate measurement techniques and demonstration of equal accuracy to slope-intercept methods.
abstract: OBJECTIVE
  We aimed to identify the most accurate single-sample glomerular filtration rate (SS-GFR) technique for all patient ages.
  
  
  METHODS
  We performed a systematic review of all published SS-GFR measurement techniques and compared the results from each test with a gold-standard nine-point 'area-under-curve' measurement of GFR as well as slope-intercept (SI-GFR) methods for 412 GFR tests.
  
  
  RESULTS
  We have shown that for patients of all ages the SS-GFR technique developed by Fleming and colleagues delivers the best accuracy and precision, with results equivalent to those calculated by SI-GFR. The median percentage difference from the gold-standard GFR for the Fleming technique is 4.8% (95% confidence interval 3.9-5.7%) and that for the three-point SI-GFR is 5.6% (95% confidence interval 4.9-6.3%). The interquartile range of the distribution of percentage difference from the gold standard is -0.23 to 11% for the Fleming method and 1.6-11% for the three-point SI-GFR.
  
  
  CONCLUSIONS
  The Fleming technique outperforms the method currently recommended by the international guidelines, and is simpler as only one equation is required for all patients instead of separate equations for adults and children. We propose that the SS-GFR technique of Fleming replace the methods currently recommended by the international and BNMS guidelines for routine measurement of GFR for expected results greater than 30 ml/min/1.73 m. A thorough system of measurement checks should be implemented for all methods of GFR assessment; the perceived lack of opportunity for quality control checks to be performed on the result of a single-sample measurement is addressed in the companion paper of this study.
authors.affiliation: aDepartment of Nuclear Medicine, Royal Free London NHS Foundation Trust, London bDepartment of Nuclear Medicine, St James's University Hospital, Leeds, UK.
authors.forename: Helena
authors.initials: H
authors.lastname: McMeekin
authors.forename: Fred
authors.initials: F
authors.lastname: Wickham
authors.forename: Mark
authors.initials: M
authors.lastname: Barnfield
authors.forename: Maria
authors.initials: M
authors.lastname: Burniston
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards*; D007223:Infant; D007231:Infant, Newborn; D007677:Kidney Function Tests / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011865:Radioisotope Dilution Technique / Q000592:standards*; D011866:Radioisotope Renography / Q000379:methods; D019275:Radiopharmaceuticals / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals