Point-of-care hemoglobin A1c margin of error alters resident management of Type 2 diabetes when near glycemic target.

Abstract

Point-of-care (POC) HbA1c is frequently used as a surrogate for serum HbA1c. We aimed to determine if resident management of type 2 diabetes changed after accounting for the + 0.5% margin of error associated with POC HbA1c devices. Residents were surveyed in an outpatient clinic regarding two of their patients with type 2 diabetes for which they had obtained a POC HbA1c. For one patient, the resident was asked if management would change if the POC HbA1c were 0.5% higher (called the positive case), and for another if management would change if POC HbA1c were 0.5% lower (negative case). Twelve of 58 (21%) cases had a change in management. Of the 27 cases where POC HbA1c was near the glycemic target (defined as POC HbA1c ≥6.0% and <8.0%), 11 (41%) resulted in a change in management while one (3%) of the 31 cases outside that interval had a change in management. POC HbA1c testing is well-suited for patients with poorly controlled type 2 diabetes while serum HbA1c testing may be more appropriate when near a patient's personalized HbA1c target since small changes in HbA1c can lead to differences in medical management.