Search

Background Information on quality requirements and objective evaluation of performance of veterinary point-of-care analyzers (POCAs) is scarce. Objectives The study was aimed at assessing observed total errors (TEobss) for veterinary hematology POCAs via meta-analysis and comparing TEobs to allowable total error (TEa) specifications based on experts′ opinions. Methods The TEobs for POCAs (impedance and laser-based) was calculated based on data from instrument validation studies published between 2006 and 2013 as follows: TEobs = 2 × CV [%] + bias [%]. The CV was taken from published studies; the bias was estimated from the regression equation at 2 different concentration levels of measurands. To fulfill quality requirements, TEobs should be < TEa. Measurands were considered as globally acceptable if > 60% of analyzers showed TEobs < TEa. Results Six studies evaluating 11 analyzers and 5 studies evaluating 5 analyzers were included for canine and feline hematology variables, respectively. For the CBC, TEobs was < 15% for canine and < 13% for feline measurands, except for HGB and platelet counts. Measurands of the CBC, excluding differential WBC and platelet counts, and HGB concentration were considered globally acceptable. For most of the cell types in the WBC differential count, TEobs was > TEa (data from 3 analyzers). Conclusion This meta-analysis is considered a pilot study. Experts′ requirements (TEobs < TEa) were fulfilled for most measurands except HGB (due to instrument-related bias for the ADVIA 2120) and platelet counts. Available data on the WBC differential count suggest an analytic bias, so nonstatistical quality control is recommended. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]