HbA1c measurement
In adults with type 2 diabetes, measure HbA1c levels at:
3–6-monthly intervals (tailored to individual needs), until the HbA1c is stable on unchanging therapy
6-monthly intervals once the HbA1c level and blood glucose lowering therapy are stable.
Use methods to measure HbA1c that have been calibrated according to International Federation of Clinical Chemistry (IFCC) standardisation.
If HbA1c monitoring is invalid because of disturbed erythrocyte turnover or abnormal haemoglobin type, estimate trends in blood glucose control using one of the following:
quality-controlled plasma glucose profiles
total glycated haemoglobin estimation (if abnormal haemoglobins)
fructosamine estimation.
Investigate unexplained discrepancies between HbA1c and other glucose measurements. Seek advice from a team with specialist expertise in diabetes or clinical biochemistry.