Measurement Uncertainty and Flagging Performance Evaluation of Sysmex XN-1500 Analyzer in an Accredited Laboratory in West Africa

Abstract

Background/Objective assess measurement uncertainty (MU) of enumerating main haematological indices using Sysmex XN-1500 analyser and flagging performance characteristics of the analyser. Methods We calculated standard MU from each possible sources of error to obtain expanded MU at a 95% level of confidence. We employed the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Milan model and the biological variation model from the EFLM database to verify that our expanded MU values were within allowable performance specifications (APS). MU was preceded by evaluating the flagging performance of the analyser. Results The MU of hemoglobin, red blood cells, haematocrit, white blood cells, and platelets generated by the Sysmex XN-1500 platform falls within the allowable APS defined by the established model. Further, we found no statistically significant differences (Mann-Whitney-U-Test, p-value = 0.2188) when the MU results for all the haematological indices obtained from our internal quality control data were compared with the external quality assurance proficiency testing results (reference method). The MU values for all the haematological indices were comparable between the Sysmex XN-1500 analyser and the existing Abbott platform (Mann-Whitney U Test, P = 0.12). The overall flagging performance of the Sysmex XN-1500 platform was excellent when compared to the gold-standard peripheral blood film examination (PBF) results, except for iRBC? Q-flags, as all iRBC? Q-flags were confirmed as false flags by PBF examination. Conclusion The MU of main haematological indices using the Sysmex XN-1500 analyser falls within the allowable APS. The flagging performance of the Sysmex XN-1500 was poor in detecting RBC inclusions.