Quality specifications for glycated hemoglobin A1c.

Berne has suggested that a change in the measured value (in per cent) of GHbA1c that is smaller than 1.0% does not lead to any therapeutic action from the clinician. Since the meeting of the "Friibergh Herrgård Seminar", April 23-24, 1990 on the "Medical Need for Quality Specifications in Laboratory Medicine" we have discussed this with our specialists at the Kuopio University Hospital and they share Berne's opinion. Keeping this in mind we have standardized our method so that the total analytical variation of the GHbA1c is small as compared to the measured biological variation of GHbA1c in nondiabetic and diabetic subjects. In this report we describe how we have succeeded in keeping the coefficient of variation of our routine method for GHbA1c analyses small enough for clinical purposes.