[Approach to the changes of HbA1c notation in health checkups]

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Endocrinology

Background:

• The Japan Diabetes Society (JDS) Committee on the Standardization of Diabetes Mellitus-Related Laboratory Testing addressed international harmonization of hemoglobin A1c (HbA1c) values.
• A decision was made to transition to National Glycohemoglobin Standardization Program (NGSP) values in clinical practice starting April 1, 2012.

Purpose of the Study:

• To document the process and significance of harmonizing HbA1c laboratory testing values in Japan.
• To outline the phased implementation of NGSP values, considering data conversion costs and system impacts.

Main Methods:

• Adoption of NGSP values for HbA1c reporting in clinical practice.
• Phased implementation: initial use of JDS values for specific health checkups alongside NGSP values in clinics and hospitals.
• Modification of laboratory analysis equipment and information systems to accommodate NGSP value reporting.

Main Results:

• Clinics and hospitals began reporting both NGSP and JDS values, while health checkup institutions initially used only JDS values.
• The JDS subsequently mandated the exclusive use of NGSP values for specific health checkups from April 1, 2013.
• Commercial laboratories adapted their systems to support the dual reporting and eventual transition to NGSP values.

Conclusions:

• The international harmonization of HbA1c values in Japan, transitioning from JDS to NGSP values, was successfully implemented.
• The harmonization is considered a significant advancement in diabetes mellitus laboratory testing standardization in Japan.
• The phased approach addressed practical challenges, ensuring continuity in patient care and data management during the transition.