Implementation of the HbA1c IFCC unit --from the laboratory to the consumer: The New Zealand experience

In 2007, an international consensus statement recommended that HbA1c results should be reported world-wide in IFCC units (mmol/mol) and also the more familiar derived percentage units using a master equation. In New Zealand, the HbA1c IFCC units have been successfully implemented and used exclusively since 3rd October 2011 (following a 2 year period of reporting both units) for both patient monitoring and the diagnosis of diabetes, with a diagnostic cut-off of ≥50 mmol/mol. The consultation process in New Zealand dates back to 2003, well before the international recommendations were made. It reflects the close cooperation between the clinical and laboratory communities in New Zealand, particularly through the agency of the New Zealand Society for the Study of Diabetes (NZSSD), a key organisation in New Zealand open to all those involved in the care of people with diabetes and the national advisory body on scientific and clinical diabetes care and standards. There was a phased process of consultation designed to increase familiarity and comfort with the new units and the final step was coupled with the adoption of HbA1c as a diagnostic test with some evidence-based pragmatism around using the rounded cut-off. Genuine clinical engagement is vital in such a process.