title: How to assess kidney function in outpatient clinics.
abstract: BACKGROUND
  In 2002, a new definition and classification of chronic kidney disease was published, and glomerular filtration rate < 60 ml/min/1.73 m(2) for 3 months or more was adapted to define chronic kidney disease irrespective of other signs of kidney damage.
  
  
  OBJECTIVE
  To discuss different ways to assess kidney function in outpatient clinics and especially in primary care.
  
  
  METHODS
  The PubMed database was searched for relevant articles.
  
  
  RESULTS
  The estimated glomerular filtration rate equations which take into account plasma creatinine, age, sex, race and body size have been developed to identify patients with chronic kidney disease formerly overlooked if the renal function had been assessed by plasma creatinine alone. Cystatin C-based equations have also been developed to enhance accuracy for individuals with whom creatinine-based estimates for kidney function are acknowledged to be less accurate.
  
  
  CONCLUSIONS
  The characteristics of the patients to whom the diagnostic test is applied can influence the sensitivity of the test. Thus, there is nowadays controversy over the best method to assess kidney function in general population.
  
  
  CONCLUSIONS
  In the overwhelming majority of patients currently treated in primary care, the CKD-EPI creatinine equation is suitable for estimating renal function. The CKD-EPIcr-cys equation would provide further reliability in individuals with a CKD-EPI creatinine eGFR of 45-59 ml/min/1.73 m(2) , but the cost of serum cystatin C analysis limits its use in everyday general practice.
authors.affiliation: Central Satakunta Health Federation of Municipalities, Harjavalta, Finland; Institute of Clinical Medicine, Family Medicine, University of Turku, Turku, Finland; Satakunta Hospital District, Pori, Finland.
authors.forename: P E
authors.initials: PE
authors.lastname: Korhonen
mesh_terms: D000554:Ambulatory Care Facilities; D003404:Creatinine / Q000032:analysis* / Q000097:blood; D055316:Cystatin C / Q000032:analysis / Q000097:blood; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests / Q000379:methods / Q000706:statistics & numerical data*; D015203:Reproducibility of Results
chemical_list: D055316:Cystatin C; D003404:Creatinine