An Evaluation of Hemoglobin A1cTest Ordering Patterns in a Primary Care Setting

Abstract

Background: To evaluate the hemoglobin A1c (HbA1c) prescription patterns by primary care physicians before the International Expert Committee (IEC) guidelines and how they have changed. Materials and Methods: The number of HbA1c tests ordered from January 2002 to December 2009 was examined in a cross-sectional study. The percentage of HbA1c results <6% and <5.5% were calculated. These cutoffs were decided after consultation of the literature regarding HbA1c values that were unlikely to have diabetic patients. Repeat HbA1c orders per patient were also tabulated. Results: 95,321 HbA1c tests were ordered. The percentage of HbA1c results <6% and <5.5%, respectively, were 36.2% and 13.8%. The percentage of HbA1c tests ordered with a result of <6% differed significantly between January 2009 to July 2009 and August 2009 to December 2009 (picked specifically because of the timing of the IEC guideline). Only 16% of patients had repeat HbA1c tests in 2009. Conclusions: It is necessary to conduct studies of HbA1c testing patterns in order to establish corrective measures to ensure proper use of the tests. Type 2 diabetes mellitus is a chronic illness with a relatively high prevalence, and glycemic control has been fundamental for the management of the disease. Hemoglobin glycation was first used 30 years ago to assess glycemia in subjects with type 2 diabetes mellitus. Since then, the hemoglobin A1c (HbA1c) assay has been the standard laboratory marker of glucose control and correlates well with long-term diabetes complications.1,2 Hemoglobin A1c is now a commonly used laboratory test for monitoring glycemia and managing type 2 diabetes mellitus.3 However, there is compelling evidence that the test is used inappropriately in clinical practice.4 There is a growing interest in HbA1c testing for a diabetes …