Inefficacy of moving average algorithm as principal quality control procedure on Technicon System H6000®

P. Tramacere, A. Marocchi, P. Gerthoux, C. Beretta, R. Brivio, P. Mocarelli

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)218-221
Number of pages4
JournalAmerican Journal of Clinical Pathology
Issue number2
Publication statusPublished - 1991


  • Bull's algorhithm
  • hematology quality control
  • red blood cell indices
  • Technicon H6000®

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


Dive into the research topics of 'Inefficacy of moving average algorithm as principal quality control procedure on Technicon System H6000®'. Together they form a unique fingerprint.

Cite this