Glycohemoglobin assays evaluated in a large-scale quality-control survey

Abstract

We report the results of a national quality-control survey on glycohemoglobin (GHb), monitored in France by the Société Française de Biologie Clinique on behalf of the authority of the "Agence du Médicament." A sample of lyophilized hemolysate was sent to 3109 laboratories. Results were obtained from 2770 laboratories. HbA1C, HbA1, and total GHb were measured by 50%, 24%, and 26% of the participants, respectively. Of these measurements, 79% of the HbA1C results and 76% of the total GHb results, but only 48% of the HbA1 results, were within the +/- 20% limits of the indicated target values. Mean values for the hemolysate ranged from 8% to 11% for HbA1C, from 7% to 12% for HbA1, and from 11% to 13% for total GHb. The interlaboratory CVs ranged from 3% to 20%, according to method used. So, methods used for GHb assay, which are based on various principles, exhibit very different analytical performances. Nonetheless, this large-scale study indicates that some techniques can support transferability of results from laboratory to laboratory.

Defining quality of care for children and adolescents with type 1 diabetes

“…This was possible in the DCCT, for example, by using a single, central laboratory for all HbA 1c measurements with careful attention to quality control (35). ACTA PAEDIATR SUPPL 425 (1998) Defining quality of care 15 (36,37). Gillery et al, for example, compared the methods and results of glycated haemoglobin levels (measured as HbA 1c , HbA 1 or total glycated haemoglobin) in 2777/3109 laboratories in France (36).…”

“…ACTA PAEDIATR SUPPL 425 (1998) Defining quality of care 15 (36,37). Gillery et al, for example, compared the methods and results of glycated haemoglobin levels (measured as HbA 1c , HbA 1 or total glycated haemoglobin) in 2777/3109 laboratories in France (36). The results show that there is huge interlaboratory variability, such that the numbers produced cannot be compared among laboratories, even those using similar methods.…”