The inappropriate use of HbA1c testing to monitor glycemia: is there evidence in laboratory data?

Rationale, Aims And Objectives: Diabetes is a chronic illness and have relatively high prevalence. Glycemic control is fundamental to the management of diabetes. Hemoglobin A1c (HbA1c) is a commonly used laboratory test to monitor glycemia and to manage diabetes. This study aimed to assess the appropriateness of the frequency of HbA1c test order with respect to the commonly approved guidelines for monitoring glycaemia of patients.

Methods: To assess the rate of inappropriate test orders, laboratory records of HbA1c tests ordered between 2002 and 2004 were evaluated. Inappropriate orders were defined as any order for a given patient that takes place within a 29- or 89-day-period following the previous HbA1c order. The effects of various parameters, like ordering clinics, the first HbA1c level, or the on-line availability of test results on test ordering were evaluated.

Results: Evaluation of test intervals showed that 10.3% of all orders and 33.8% of the inpatients' orders were performed within 29 days, 35.5% of all orders and 55% of the inpatients' orders were within 89 days.

Conclusions: Inappropriate laboratory utilization of HbA1c testing is very common especially in the inpatient clinics. We think that the application of the guidelines may decrease unnecessary health expenditure.