Average blood glucose and the A1C test. The A1C test (also known as HbA1C or glycated hemoglobin) provides a good general indication of diabetes control. It is used to indicate a person’s average blood glucose level over the past few months.Unlike daily blood glucose test results, which are reported as mg/dL, A1C is reported as a percentage.verage blood glucose and the A1C test. The A1C test (also known as HbA1C or glycated hemoglobin) provides a good general indication of diabetes control. It is used to indicate a person’s average blood glucose level over the past few months.