Abstract:
The objective of this study was to identify cost-effective conditions for HbA1c testing if prescribed at least once a year. A retrospective medical record review was conducted using the secondary databases of 4,906 type-2 diabetic outpatients in two tertiary-care hospitals in the fiscal year 2012 and compared the effectiveness of the two approaches of HbA1c testing in indicating inconsistent results with fasting plasma glucose (FPG): (1) HbA1c testing after reviewing of FPG patterns, and (2) the unconditional HbA1c test, with the cut-off point of FPG at 130 mg/dL and 150 mg/dL as a criteria for normal FPG. The study findings indicated that, using the FPG cut-off point at 130 mg/dL, having HbA1c after two and three consecutively normal FPG tests (OO and OOO patterns) were less effective than the unconditional HbA1c test (p-value = 0.046 and 0.037, respectively). The HbA1c test after two abnormal and one normal consecutive FPG tests (XXO pattern) was more effective than the unconditional HbA1c test (p-value = 0.019). Using the FPG cut-off point at 150 mg/dL, it was found that having HbA1c after conflicting selected two-consecutive and three-consecutive FPG tests (XO, OX, OXO, XXO, and OOX patterns) were more effective than the unconditional HbA1c test (p-value = < 0.001, 0.031, 0.045, < 0.001, and 0.018, respectively). In conclusion, reviewing of FPG patterns prior to deciding to take HbA1c test can lead to higher value than prescribing the tests randomly.