IFCC reference system for measurement of haemoglobin A1c in human blood and the national standardization schemes in the United States, Japan, and Sweden: a method-comparison study
Hoelzel et al. · 2004 · Clinical Chemistry 50(1):166-174
What this work gives Aellic
Method comparison giving the IFCC to NGSP master equation, NGSP % = 0.915 x IFCC % + 2.15. Since IFCC results are reported in mmol/mol, the same relation reads NGSP % = 0.09148 x IFCC mmol/mol + 2.152 (as published by NGSP), the conversion applied when a lab sheet reports HbA1c in mmol/mol.
Correction of 25 October 2026
The registry presented the mmol/mol form of the equation as the paper's result. The paper reports it in IFCC percent; the mmol/mol unit was introduced later, and the mmol/mol constants are the form NGSP publishes.
The entry on the register was wrong. It was not replaced but kept, with what holds instead standing next to it.
Where this sits in the engine
This work is on the register, but nothing computes with it today, mostly because the feature it belongs to has not been built yet. It is listed so the numbers on the overview do not claim more than they carry.