In 1994 in the Czech Republic external quality evaluation of haemograms was started. Quality was evaluated by sending control samples to laboratories and by comparing the results of their assessment with the correct value. A permitted range to results was assessed: for platelets 24%, for leucocyte 20% and for erythrocytes, haemoglobin, haematocrit and the mean corpuscular volume (MCV) 10%. The relative error of blood cell count was expressed by means of a coefficient of variance. The error declined during the period of evaluation, during the last cycle it was 4% for erythrocytes 8% for leucocytes and 10% for platelets. Assessment of haemoglobin was of all components of the haemorgram associated with the least error, assessment of the haematocrit was less successful. Least accurate were laboratories which use manual methods (success rate cca 70%), more successful were assessments made by semi-automatic analyzers for blood counts (85%), automatic analyzers were successful in 95%. The participating laboratories obtained certificates for well assessed parameters.

Keywords: Czech Republic; Hematologic Tests /standards/; Humans; Laboratories /standards/; Quality Control