title: Analytical performance of 17 general chemistry analytes across countries and across manufacturers in the INPUtS project of EQA organizers in Italy, the Netherlands, Portugal, United Kingdom and Spain.
abstract: BACKGROUND
  Optimum patient care in relation to laboratory medicine is achieved when results of laboratory tests are equivalent, irrespective of the analytical platform used or the country where the laboratory is located. Standardization and harmonization minimize differences and the success of efforts to achieve this can be monitored with international category 1 external quality assessment (EQA) programs.
  
  
  METHODS
  An EQA project with commutable samples, targeted with reference measurement procedures (RMPs) was organized by EQA institutes in Italy, the Netherlands, Portugal, UK, and Spain. Results of 17 general chemistry analytes were evaluated across countries and across manufacturers according to performance specifications derived from biological variation (BV).
  
  
  RESULTS
  For K, uric acid, glucose, cholesterol and high-density density (HDL) cholesterol, the minimum performance specification was met in all countries and by all manufacturers. For Na, Cl, and Ca, the minimum performance specifications were met by none of the countries and manufacturers. For enzymes, the situation was complicated, as standardization of results of enzymes toward RMPs was still not achieved in 20% of the laboratories and questionable in the remaining 80%.
  
  
  CONCLUSIONS
  The overall performance of the measurement of 17 general chemistry analytes in European medical laboratories met the minimum performance specifications. In this general picture, there were no significant differences per country and no significant differences per manufacturer. There were major differences between the analytes. There were six analytes for which the minimum quality specifications were not met and manufacturers should improve their performance for these analytes. Standardization of results of enzymes requires ongoing efforts.
authors.forename: Cas
authors.initials: C
authors.lastname: Weykamp
authors.forename: Sandra
authors.initials: S
authors.lastname: Secchiero
authors.forename: Mario
authors.identifier: http://orcid.org/0000-0002-0270-1711
authors.initials: M
authors.lastname: Plebani
authors.forename: Marc
authors.initials: M
authors.lastname: Thelen
authors.forename: Christa
authors.initials: C
authors.lastname: Cobbaert
authors.forename: Annette
authors.initials: A
authors.lastname: Thomas
authors.forename: Nuthar
authors.initials: N
authors.lastname: Jassam
authors.forename: Julian H
authors.initials: JH
authors.lastname: Barth
authors.forename: Carmen
authors.initials: C
authors.lastname: Perich
authors.forename: Carmen
authors.initials: C
authors.lastname: Ricós
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Faria
mesh_terms: D001774:Blood Chemical Analysis; D002118:Calcium / Q000097:blood; D002712:Chlorides / Q000097:blood; D002784:Cholesterol / Q000097:blood*; D004798:Enzymes / Q000097:blood* / Q000378:metabolism; D005947:Glucose / Q000032:analysis*; D006801:Humans; D009426:Netherlands; D011174:Portugal; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D013030:Spain; D006113:United Kingdom; D014527:Uric Acid / Q000097:blood*
chemical_list: D002712:Chlorides; D004798:Enzymes; D014527:Uric Acid; D002784:Cholesterol; D012964:Sodium; D005947:Glucose; D011188:Potassium; D002118:Calcium