HbA1c: A comparison of NGSP with IFCC transformed values

The IFCC converted to NGSP values were significantly different from the previously used NGSP-certified method. The differences between the 2 methods are of sufficient magnitude that HbA1c results from these methods are not interchangeable. The IFCC method being scientifically superior in concept and design should replace the NGSP method. New HbA1c targets for DM management need to be established for the IFCC method.