title: European concerted action on anticoagulation. Quality assessment of the CoaguChek Mini and TAS PT-NC point-of-care whole-blood prothrombin time monitors.
abstract: BACKGROUND
  International Normalized Ratios (INRs) for prothrombin time obtained with the CoaguChek Mini and TAS (RapidPointCoag) PT-NC systems are markedly different and also differ from the "true" INR. There is therefore a need for local quality assessment (QA) of the two systems.
  
  
  METHODS
  A set of 60 lyophilized artificially depleted and 60 lyophilized coumarin plasmas were tested at 10 centers on both point-of-care testing monitors. Subsets of three and five plasmas were selected as QA plasmas and compared with the remaining 55 to assess the relative ability of the systems to characterize performance at the individual centers. The incidence of aberrant results (outliers; >15% deviation from the true INR) was also recorded. The expected incidence with the QA plasmas was calculated and compared.
  
  
  RESULTS
  On both systems, INR with the common sets of 55 lyophilized plasmas varied considerably between centers. With the TAS PT-NC, subsets of five and three European Concerted Action on Anticoagulation (ECAA) artificially depleted plasmas gave good correlation with the 55 plasmas, but the coumarin plasmas performed less well. With the CoaguChek Mini, correlation was good with sets of five artificially depleted QA plasmas and reasonable with three but was less satisfactory with the coumarin plasmas. Outliers were detected with both types of plasmas on both test systems but with variable success.
  
  
  CONCLUSIONS
  With the TAS PT-NC, three ECAA artificially depleted lyophilized plasmas provided reliable QA, but five lyophilized coumarin plasmas were required. With the CoaguChek Mini, five artificially depleted plasmas gave reliable QA but coumarin plasmas gave poorer results. ECAA QA plasmas provide a local system for checking INRs obtained with monitors of both types.
authors.affiliation: European Concerted Action on Anticoagulation Central Facility, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom. ecaa@man.ac.uk
authors.forename: Leon
authors.initials: L
authors.lastname: Poller
authors.forename: Michelle
authors.initials: M
authors.lastname: Keown
authors.forename: Nikhil
authors.initials: N
authors.lastname: Chauhan
authors.forename: Anton M H P
authors.initials: AM
authors.lastname: van den Besselaar
authors.forename: Armando
authors.initials: A
authors.lastname: Tripodi
authors.forename: Caroline
authors.initials: C
authors.lastname: Shiach
authors.forename: Jorgen
authors.initials: J
authors.lastname: Jespersen
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D005060:Europe; D005612:Freeze Drying; D006403:Hematologic Tests / Q000295:instrumentation*; D006801:Humans; D007391:International Cooperation; D019934:International Normalized Ratio; D019095:Point-of-Care Systems; D011517:Prothrombin Time / Q000295:instrumentation* / Q000592:standards; D011786:Quality Control; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin