NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update

Diabetes: HbA1c as a diagnostic test

NHSGGC has adopted the WHO recommendation for the use of HbA1c as a diagnostic tool for diabetes. Guidance is included in the updated Diabetes guideline for diagnosis.

HbA1c gives a false (usually low) result in haematological disorders especially those with altered red cell lifespan such as anaemia and haemoglobinopathies, and must be used with caution in these situations.


Patients presenting with osmotic symptoms must be assessed urgently with a capillary blood glucose and urine ketone assessment with immediate referral to secondary care if ketone positive, without waiting for the HbA1c result.


Patients diagnosed with Type 2 diabetes should then be managed according to the NHSGGC guideline.