HbA1c: changing units, changing minds – mission accomplished?

Abstract

The case for a universal reference standard for glycated haemoglobin is accepted, and after many years (1995–2010) this has now been achieved through the National Glycohemoglobin Standardization Program/International Federation of Clinical Chemistry (IFCC) initiative. In contrast, the transition between 2009 and 2012 to worldwide reporting of the new measurement in SI units (mmol/mol) has been less satisfactory because of weak rationale, divergent timescales for implementation in different countries and difficulties for patients and practitioners in using the new units in real clinical practice. To date, only the UK and New Zealand have moved to reporting in IFCC units alone, while other countries have taken a more measured view. The new reporting units are of uncertain value to patients and are unlikely to improve delivery of care, while occupying much bureaucratic and clinical time.