title: Regional variation in use of exogenous and endogenous glomerular filtration rate (GFR) markers in Sweden.
abstract: BACKGROUND
  Markers of renal function (glomerular filtration rate (GFR)) are frequently used in the Swedish health care. GFR is usually estimated based on plasma creatinine concentration, but plasma cystatin C concentration, creatinine clearance, iohexol clearance, and (51)Cr-EDTA clearance are also used. These markers are all part of the daily patient care, but there is little specific information on the clinical use of these markers. The aim of this study was to compare the use of these various GFR markers in different parts of Sweden and potential changes over time.
  
  
  METHODS
  Retrospective study using questionnaires to collect information for the years 2006-2009 divided per county on the specific use of GFR markers with type of test reports.
  
  
  RESULTS
  Plasma/serum creatinine concentration (96%) is by far the dominating GFR marker in Sweden, while cystatin C concentration (3.5%), creatinine clearance (0.1%), iohexol clearance (0.1%), and 51Cr-EDTA clearance (0.1%) are less frequently used. The use of GFR markers, including creatinine, continues to increase on a national level with the exception of creatinine clearance and 51Cr-EDTA clearance. There were considerable variations between different counties in the use of GFR markers and the type of test reports that the laboratories provided.
  
  
  CONCLUSIONS
  The inter-county variations of GFR markers used in Sweden are large and indicate that savings associated with optimized test utilization in this regard could be substantial. Regional habits and traditions are likely to influence the variations in GFR marker use.
authors.affiliation: SBU, Stockholm, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Vilhelmsdotter Allander
authors.forename: Lars-Åke
authors.initials: LÅ
authors.lastname: Marké
authors.forename: Björn
authors.initials: B
authors.lastname: Wihlen
authors.forename: Maria
authors.initials: M
authors.lastname: Svensson
authors.forename: Carl-Gustaf
authors.initials: CG
authors.lastname: Elinder
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
mesh_terms: D015415:Biomarkers / Q000097:blood*; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005919:Glomerular Filtration Rate; D006801:Humans; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013548:Sweden
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine