Variation between Point-of-care and Laboratory HbA1c testing in Clinical Practice

Abstract

Objective: The aim of this study was to identify potential disparities between point-of-care testing (POCT) and laboratory hemoglobin A1c (HbA1c) reporting at a Federally Qualified Health Center (FQHC). Methods: The electronic medical record was reviewed to identify POCT HbA1c done at a FQHC and centralized laboratory venous HbA1c performed on the same day. Manual data extraction was used to identify potential variables that could account for disparities between POCT and laboratory testing. Results: A total of 42 samples in 40 patients were identified. The median HbA1c difference was 1.5 mmol/mol (0.15%) and ranged from -26 to 52 mmol/mol (-2.4 to 4.8%). Of the patients in the study, two had underlying comorbidities that could affect the POCT HbA1c. Conclusion: Point-of-care HbA1c testing should not be used in solidarity to diagnosis pre-diabetes and diabetes. When using HbA1c results to guide therapy, self-monitoring of blood glucose and symptoms of both hypo- and hyperglycemia should be correlated to help determine appropriate therapy.