How often should HbA1c be measured in a diabetic patient for monitoring?

HbA1c should be checked every 3 months (quarterly) in patients with diabetes whose treatment has recently changed or who are not meeting glycemic goals. This interval aligns with the approximately 3-month lifespan of red blood cells, allowing sufficient time for the value to reflect changes in glucose control. In well-controlled patients at goal, testing every 6 months may be acceptable. In dentistry, recent HbA1c results (within 3 months) help assess the patient's current glycemic status before invasive procedures.