Inefficacy of moving average algorithm as principal quality control procedure on Technicon System H6000.
Bull's algorithm, in its "revisited" formulation, represents one of the main quality control (QC) procedures in several multichannel automatic hematological analyzers. Its efficacy, however, is reduced in the theoretical event that red blood cells (RBC) and hemoglobin (Hgb) undergo a concomitant analytical drift while mean corpuscular volume (MCV) remains unaffected, so that a null effect is registered on the related erythrocytic indices: mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). This particular phenomenon has been observed on the Technicon System H6000. Routine daily work was kept in control through the use of commercial controls and fresh blood samples: a reproducible positive drift of two directly measured erythrocytic parameters (RBC and Hgb) and of the calculated hematocrit (Hct) was observed proportional to the time of continuous use of the instrument. The usefulness of Bull's QC scheme was greatly reduced: it failed to detect "out of control" situation in 38%, 15%, and 13% of cases in the monitoring of MCV, MCH, and MCHC, respectively, when compared with the traditional 2 SD limits on QC samples.
Tramacere
P
P
University Department of Pathology, Hospital of Desio, Milan, Italy.
Marocchi
A
A
Gerthoux
P
P
Beretta
C
C
Brivio
R
R
Mocarelli
P
P
D000465:Algorithms; D001322:Autoanalysis / Q000592:standards / Q000706:statistics & numerical data; D001772:Blood Cell Count / Q000295:instrumentation*; D004909:Erythrocyte Indices; D006400:Hematocrit / Q000295:instrumentation; D006452:Hemoglobinometry / Q000295:instrumentation; D006801:Humans; D007958:Leukocyte Count / Q000295:instrumentation*; D011786:Quality Control