The determination of the ratio of Hemoglobin A compared to total Hemoglobin present in a sample. The measurement may be expressed as a ratio or percentage. [ NCI ]. The trait is Hemoglobin A to Total Hemoglobin Ratio Measurement (EFO_0009209, an Experimental Factor Ontology entry). Also known as: HGBAHGB, Hemoglobin A/Total Hemoglobin, Percent Hemoglobin A.