Background
The prevalence of undiagnosed diabetes mellitus is estimated to be 500,000 in the Australian community1, with relatively high proportions in hospitalised patient cohorts. Screening for diabetes in hospitalised patients has been limited by the lack of an optimal screening test and the confounding effect of stress hyperglycaemia on random BGLs. We aim to evaluate the success of using the HbA1c to detect previously undiagnosed diabetes in patients presenting to the emergency department.
Methods
All patients that had blood taken in the emergency department had HbA1cs performed if they had random BGL≥10mmol/L. The results from a 6-month period were retrospectively reviewed to determine if these patients had previously known diabetes and if HbA1c≥6.5%, whether a diagnosis of diabetes was recognised during the admission.
Results
Over the 6-month study period 1195 patients had random BGL≥10mmol/L and 945 patients of these had an HbA1c≥6.5%. 12% (113/945) weren’t previously known to have diabetes. This was consistent across random BGL ranges (13% for BGLs 10.0-12.0mmol/L, 12% for BGLs 12.1-14.0mmol/L, 12% for BGLs 14.1-16.0mmol/L and 10% for BGLs≥16.1mmol/L). Only 39/113 (33.6%) of the patients without previously known diabetes were diagnosed during their admissions.
Conclusion
If the HbA1c is used in this manner of targeted screening in hyperglycaemic patients presenting to our emergency department, a substantial number of new cases can be identified. This could allow for early management interventions which are associated with a reduced risk of developing macrovascular and microvascular complications. Further studies are required to determine whether a lower BGL filter should be used to select cases for HbA1c screening. This screening method needs to be paired with a clear and simple hospital policy to deal with abnormal results.