Hi Broads,
In many respects it does exactly that, otherwise what would be the point in having it done. In the early stages HBA1C should be tested every 3 months, and each test covers a 3 month period, so will tell your GP how your control has been since the last test. That will determine whether he/she thinks you can control things with diet and exercise alone; or diet, exercise and medication; and what kind of medication. What the GP will be looking for is a steady reduction each time you are tested.