title: Analysis of the concordance between the estimated values of creatinine clearance using the Cockcroft-Gault equation and the real value determined in patients from the Hospital Clínica Bíblica.
abstract: OBJECTIVE
  to analyze the effect of the modifications in the Cockcroft-Gault equation for creatinine clearance rate determination (CrCl) and its concordance with the real value determined from 24-hours urine collection in a sample of Latin American patients hospitalized in San José de Costa Rica.
  
  
  METHODS
  an observational, retrospective study, with patients submitted to a 24-hour urine collection test, and who met the inclusion criteria. The real and estimated values of creatinine clearance were determined, and their concordance was measured by applying the Intraclass Correlation Coefficient; a descriptive analysis of data was also conducted.
  
  
  RESULTS
  there were 507 subjects (61% men); their age was described (ME = 60 years SD = 17 years), as well as their height (ME = 1.66 m SD = 0.09 m), current weight (ME =75 kg SD = 15 kg), body mass index (ME = 27.3 kg/m2 SD = 4.76 kg/m2) and endogenous creatinine clearance rates (ME = 69.72 ml/min SD = 33 ml/min). The best concordance with the equation was obtained with current weight values and serum creatinine without rounding.
  
  
  CONCLUSIONS
  the application of the Cockcroft-Gault equation that matches more closely the real value is the one that uses current weight and does not round creatinine values below 1 mg/dL. It is suggested to conduct a prospective analysis, determining other variables that could affect CrCl real measures, and to replicate this methodology in specific populations. *ME: Mean **SD: Standard Deviation.
authors.affiliation: Department of Pharmacology, Toxicology, and Drug Dependence of the School of Pharmacy, Universidad de Costa Rica. Clinical Pharmacist, Hospital Clínica Bíblica, San José.. jose.chaverri@ucr.ac.cr.
authors.forename: Jose Miguel
authors.initials: JM
authors.lastname: Chaverri-Fernández
authors.affiliation: Head of Pharmacy at the Hospital Clínica Bíblica, San José.. jose.chaverri@ucr.ac.cr.
authors.forename: Esteban
authors.initials: E
authors.lastname: Zavaleta-Monestel
authors.affiliation: Clinical Pharmacist. Hospital Clínica Bíblica, San José.. jose.chaverri@ucr.ac.cr.
authors.forename: Jose Pablo
authors.initials: JP
authors.lastname: Díaz-Madriz
authors.affiliation: Department of Pharmacology, Toxicology and Drug Dependence of the School of Pharmacy, Universidad de Costa Rica.. jose.chaverri@ucr.ac.cr.
authors.forename: Angie
authors.initials: A
authors.lastname: Ortiz-Ureña
authors.affiliation: Intern Students. University of Medical Sciences UCIMED-Hospital Clínica Bíblica. Costa Rica.. jose.chaverri@ucr.ac.cr.
authors.forename: Monica
authors.initials: M
authors.lastname: Ramírez-Hernández
authors.affiliation: Intern Students. University of Medical Sciences UCIMED-Hospital Clínica Bíblica. Costa Rica.. jose.chaverri@ucr.ac.cr.
authors.forename: Karina
authors.initials: K
authors.lastname: Trejos-Morales
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003364:Costa Rica; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D007677:Kidney Function Tests / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003404:Creatinine