The determination of the ratio of hemoglobin A1 compared to total hemoglobin present in a sample. The measurement may be expressed as a ratio or percentage. [ NCI ]. The trait is EFO_0009210 (Hemoglobin A1 to Total Hemoglobin Ratio Measurement). Also known as: HGBA1HGB, Hemoglobin A1/Total Hemoglobin.