Operating scheme and experience of executing internal comparisons of blood cell analysis in a clinical laboratory.

BACKGROUND

The aim of the study was to perform an internal comparison of blood cell analyses: white blood cell (WBC) and platelet (PLT) counts in a clinical laboratory.

METHODS

Instrument comparison: Based on EP9-A2 of the Clinical Laboratory and Standard Institute (CLSI) and the statistics program of External Quality Assessment (EQA), we set 1/2CLIA'88 as our quality standard and used a Beckman coulter LH750 as the reference. We then compared this to another 4 blood analyzers: the Beckman Coulter Gen-S, ABX pentra 60, and the Sysmex XT2000i and XS-800i, including the Beckman Coulter Gen-S in manual mode. Personnel comparison: WBC and PLT counts were performed on five samples by 13 technicians at random. Two statistics programs were used to calculate the bias of each technician. The results were compared with the 1/2 CLIA'88 standard to evaluate staff performance.

RESULTS

All instrument comparisons met our quality standards of WBC < 7.5% and PLT < 12.5%. However, five technicians did not achieve satisfactory results of the WBC count in the first assessment. The coefficient of variation (CV) among qualified staff assessing five samples ranged from 8.51% to 12.2%, but all exceeded the 1/2 CLIA'88 quality standard; however, the CVs of 2 samples among qualified staff were approximately 20%, but after strict training this variability reduced significantly to approximately 5%.

CONCLUSIONS

Instrument comparisons demonstrated achievement of quality goals under rigorous calibration and quality control, but CVs were comparatively large. This improved following strict training, so a laboratory should emphasize the training and assessment of staff and evaluation of the actual situation when selecting a qualification program.