Limits of performance for measurement of blood haemoglobin concentration, number concentration of erythrocytes, and erythrocyte volume fraction in interlaboratory trials: Results of the Finnish proficiency testing programme in haematology

Abstract

Limits of performance for measurement of blood haemoglobin concentration, number concentration of erythrocytes, and erythrocyte volume fraction are presented. The limits of performance are based on actual performance by the participants of the Finnish external quality control programme in haematology. In evaluation of a laboratory's performance in measuring blood haemoglobin (Fe) concentration, all values within ±0.20 mmol/l of the corrected mean are considered to represent ‘good’ performance; those between ±0.20 and ±0.40 mmol/l represent ‘acceptable’ performance and values outside ±0.40 mmol/l are ‘not acceptable’. Similarly, in measuring number concentration of erythrocytes the limits of ±0.2 × 10¹²1⁻-¹ and ±0.4 × 10¹²1⁻-¹ and in measuring erythrocyte volume fraction the limits of ±0.01 and ±0.02 were established. The limits of performance proved to be readily attainable by the survey participants.

Key Words:

• blood
• erythrocyte count
• haematocrit
• haematology
• haemoglobin concentration
• quality control