title: Does reporting estimated glomerular filtration rate affect ordering of timed urine collections?
abstract: BACKGROUND
  The National Kidney Foundation recommends reporting estimates of glomerular filtration rate (eGFR) rather than timed urine collections. When 2 of the 3 major hospitals in our region began reporting eGFR at different times we recognized a natural experiment.
  
  
  METHODS
  We conducted a retrospective, observational study at the 3 major hospitals in Chattanooga, Tennessee. Data were collected on the frequency of timed urines during a 41/2-year period. Regression analysis was used to study the association of the rate of ordering timed urines adjusted for other factors.
  
  
  RESULTS
  There was a marked drop in the rate of ordering of timed urines at all 3 hospitals from a mean of 21.8 per 1000 admissions in the first 4 quarter years of the study to 10.9 in the last 4 (15th-18th) quarter years. The drop began before the reporting of eGFR at any hospital. The reporting of eGFR had a small effect (-1.7 per 1000 hospital admissions) that was not statistically significant (P = 0.15).
  
  
  CONCLUSIONS
  There has been a marked drop in the ordering of timed urines in our region. The decline began before the reporting of eGFR at 2 of the hospitals and therefore is attributable to other factors.
authors.affiliation: Division of Nephrology, University of Tennessee College of Medicine, Memphis, TN 37379, USA.
authors.forename: Vikul
authors.initials: V
authors.lastname: Patel
authors.forename: Umesh
authors.initials: U
authors.lastname: Yalavarthy
authors.forename: Normans A
authors.initials: NA
authors.lastname: Desbiens
mesh_terms: D005919:Glomerular Filtration Rate; D006801:Humans; D012044:Regression Analysis; D012189:Retrospective Studies; D013048:Specimen Handling; D014556:Urine