This notice formally retracts all prior communications regarding the planned implementation of new HbA1c target limits for prediabetes, diabetes diagnosis, treatment monitoring, and estimated average glucose (eAG) reporting. These changes will not proceed on 1 June as previously advised, to align with the nationally coordinated update later this year.
Reference Interval Update for Roche Methodology
We will proceed with updating the HbA1c reference interval on 1 June to <42 mmol/mol to reflect the characteristics of the Roche methodology, following our earlier transition as part of national harmonisation efforts. Analytical method changes can sometimes result in slight shifts in baseline values due to differences in assay design and detection principles. In such cases, revising the reference interval is a routine laboratory practice to ensure consistency in clinical interpretation. During method comparison, the Roche assay remained within the allowable analytical specifications across the measurable range:
- ±4% for values up to 45 mmol/mol, and
- ±8% for values >45 mmol/mol
While this level of analytical variation is technically not expected to impact clinical management significantly, we acknowledge feedback from some primary care providers regarding a noted slight upward shift in some patient results.
We recommend repeating HbA1c testing in approximately one month to establish a new baseline for your patient if results appear inconsistent with clinical expectation. Although no concerns were raised by diabetes specialists, we recognise that patients with borderline or high-normal HbA1c levels in primary care settings may be most affected by the methodological shift. Borderline HBA1C values still merit clinical attention, typically beginning with lifestyle and dietary intervention before initiating pharmacological treatment.
We remain confident in the accuracy of the Roche HbA1c assay. For further information or to discuss specific cases, please contact your local Awanui laboratory team.
Melissa Yssel
Clinical Lead – Chemical Pathology, Awanui Group