Issue: 2014 > November > original article

Differences in interpretation of haemoglobin A1c values among diabetes care professionals

E. Lenters-Westra, R.K. Schindhelm, H.J.G. Bilo, K.H. Groenier, R.J. Slingerland


Background: To assess the expected precision of HbA1c
measurements and the magnitude of HbA1c changes
eliciting the advice to change treatment among diabetes
care professionals. Methods: A seven-item questionnaire was sent to participants through a website. The survey focused on physicians and nurses involved in diabetes care. Results: In total, 104 physicians, 177 diabetes specialist nurses, and 248 primary care nurses responded to the survey. A large number of the nurses (44%) and only a small number of the physicians (4%) were not aware of the inherent uncertainty of HbA1c results. Nurses considered adjusting therapy based on very small changes in HbA1c whereas physicians in general adhere to 0.5% (5.5 mmol/mol) as a clinically meaningful cut-off point. After therapy adjustment, a very small (0.1%) or no increase in HbA1c was considered to be significant enough to conclude that
glucose regulation has worsened by 49% of the nurses and only 13% of the physicians. Conclusion: Significant differences exist in the interpretation of changes in HbA1c results between physicians and nurses. Nurses consider therapy changes based on very small changes in HbA1c, whereas physicians preferably agree to the clinically relevant change of 0.5% (5.5 mmol/mol). Changing therapy based on relatively small changes in HbA1c might lead to undue adjustments in the treatment of patients with diabetes. There is a clear need for more training for all diabetes care professionals about both the clinical significance and accuracy of HbA1c measurements.