Repeat patient testing‐quality control compared to commercial quality control material for the Sysmex XT‐2000iV hematology analyzer in a multi‐site veterinary laboratory

Abstract

AbstractBackgroundQuality control material (QCM) for hematology in veterinary laboratories is limited, and repeat patient testing quality control (RPT‐QC) is an alternative method using excess matrix‐specific samples.ObjectivesThis study aimed to determine if median differences between RPT‐QC analyses for each time interval for RBC, HGB, HCT, and WBC were the same, determine if unified RPT‐QC limits can be applied to a network of veterinary laboratories, compare the performance of RPT‐QC to commercial QCM for the reference analyzer and evaluate the experience over a 4 month period and design, improve and implement an automated spreadsheet for RPT‐QC data management.MethodsThe potential to unify individual analyzer RPT‐QC limits for red blood cells (RBC), hematocrit (HCT), hemoglobin (HGB), and white blood cells (WBC) on multi‐site Sysmex XT‐2000‐iV analyzers was explored by a difference of means test and confidence interval determination for the median difference for each network analyzer in comparison to the network reference analyzer. User experience of an automated RPT‐QC data management Excel spreadsheet was collected by user feedback during monthly meetings. Numbers of out‐of‐control results and the root causes for these for RPT‐QC were compared against those of a commercial QCM over a 4‐month period.ResultsDifferences between individual analyzer RPT‐QC limits were too large to allow for unification of network limits. The automated spreadsheet successfully highlighted out‐of‐control events for RPT‐QC. Trends or shifts were more frequent for commercial QCM based on observed performance and a 1–2.5 s QC rule than for RPT‐QC. Following routine troubleshooting, RPT‐QC out‐of‐control events were resolved with an alternative RPT‐QC sample indicating random error associated with excessive deterioration. Use of an automated spreadsheet for recording RPT‐QC, documentation and troubleshooting of out‐of‐control events, and collating monthly summary calculations were considered an asset in laboratory quality management.ConclusionsRPT‐QC can be successfully implemented and integrated into a multi‐site veterinary laboratory. Individual analyzer RPT‐QC limit generation is recommended. The deterioration of commercial QCM caused shifts or trends in QC results, which initiated more repeat analyses and investigations than did RPT‐QC.