title: Comparison of the Equil2 program and other methods for estimating the ion-activity product of urinary calcium oxalate: a new simplified method is proposed.
abstract: BACKGROUND
  We aimed to develop a new simplified method to determine the urinary calcium-oxalate saturation.
  
  
  METHODS
  The ion-activity product (AP) of urinary calcium oxalate was estimated in 345 clinical urine specimens (all 2.5 hour collections) using the Equil2 computer program and several other methods, and the results were compared. A new index using 4 parameters was created using multiple regression analysis.
  
  
  RESULTS
  Our new simplified method (the AP(CaOx) index EQ2) provided a better approximation to the Equil2 method (r = 0.9897) than other conventional methods.
  
  
  CONCLUSIONS
  This new method requiring 4 factors (urinary calcium, magnesium, oxalate, and citrate concentrations) is simple and clinically usable.
authors.affiliation: Department of Urology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ogawa
authors.forename: T
authors.initials: T
authors.lastname: Hatano
mesh_terms: D002129:Calcium Oxalate / Q000652:urine*; D002624:Chemistry, Clinical / Q000379:methods*; D006801:Humans; D008297:Male; D014556:Urine / Q000737:chemistry*
chemical_list: D002129:Calcium Oxalate