Central to the diagnosis and management of patients with diabetes mellitus is the measurement of hemoglobin A1c (HbA1c).  Major studies have defined the therapeutic targets of HbA1c in order to reduce the risk of the complications arising from the disease.  Through the NGSP, proficiency testing (PT) has played an important role to uphold the standardization of HbA1c assays and support the reliability of results across the globe.  PT provides an objective assessment of method performance in the hands of the end-user such that HbA1c results continue to be traceable to the reference methods.  The analytical improvements over time have led to the international endorsement of HbA1c as a screening and diagnostic test for diabetes.

Learning objectives:
1. State the benefits of an accuracy-based proficiency testing scheme for HbA1c.
2. Understand the traceability of HbA1c assays to the NGSP and IFCC reference methods.