title: Quality requirements for veterinary hematology analyzers in small animals-a survey about veterinary experts' requirements and objective evaluation of analyzer performance based on a meta-analysis of method validation studies: bench top hematology analyzer.
abstract: BACKGROUND
  Scarce information exists about quality requirements and objective evaluation of performance of large veterinary bench top hematology analyzers.
  
  
  OBJECTIVE
  The study was aimed at comparing the observed total error (TEobs ) derived from meta-analysis of published method validation data to the total allowable error (TEa ) for veterinary hematology variables in small animals based on experts' opinions. Ideally, TEobs should be < TEa .
  
  
  METHODS
  An online survey was sent to veterinary experts in clinical pathology and small animal internal medicine for providing the maximal allowable deviation from a given result for each variable. Percent of TEa = (allowable median deviation/clinical threshold) * 100%. Second, TEobs for 3 laser-based bench top hematology analyzers (ADVIA 2120; Sysmex XT2000iV, and CellDyn 3500) was calculated based on method validation studies published between 2005 and 2013 (n = 4). The percent TEobs = 2 * CV (%) + bias (%). The CV was derived from published studies except for the ADVIA 2120 (internal data), and bias was estimated from the regression equation.
  
  
  RESULTS
  A total of 41 veterinary experts (19 diplomates, 8 residents, 10 postgraduate students, 4 anonymous specialists) responded. The proposed range of TEa was wide, but generally ≤ 20%. The TEobs was < TEa for all variables and analyzers except for canine and feline HGB (high bias, low CV) and platelet counts (high bias, high CV).
  
  
  CONCLUSIONS
  Overall, veterinary bench top analyzers fulfilled experts' requirements except for HGB due to method-related bias, and platelet counts due to known preanalytic/analytic issues.
authors.affiliation: Department of Clinical Pathophysiology and Clinical Pathology, Faculty of Veterinary Medicine, Justus-Liebig-University, Gießen, Germany.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Cook
authors.affiliation: Department of Clinical Pathophysiology and Clinical Pathology, Faculty of Veterinary Medicine, Justus-Liebig-University, Gießen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Moritz
authors.affiliation: IDEXX Laboratories, Ltd, Grange House, Wetherby, UK.
authors.forename: Kathleen P
authors.initials: KP
authors.lastname: Freeman
authors.affiliation: Department of Clinical Pathophysiology and Clinical Pathology, Faculty of Veterinary Medicine, Justus-Liebig-University, Gießen, Germany. natali.bauer@vetmed.uni-giessen.de.
authors.forename: Natali
authors.initials: N
authors.lastname: Bauer
mesh_terms: D000818:Animals; D002415:Cats; D004285:Dogs; D006405:Hematology / Q000295:instrumentation* / Q000592:standards; D010976:Platelet Count; D012107:Research Design; D011795:Surveys and Questionnaires; D014730:Veterinary Medicine / Q000295:instrumentation* / Q000592:standards
keywords: Medical decision threshold; quality goal index; six sigma metrics; total allowable error