The determination of the ratio of Hemoglobin S compared to total Hemoglobin present in a sample. The measurement may be expressed as a ratio or percentage. [ NCI ]. The trait is EFO_0009224 (Hemoglobin S to Total Hemoglobin Ratio Measurement). Also known as: HGBSHGB, Hemoglobin S Measurement, Hemoglobin S/Total Hemoglobin, Percent Hemoglobin S.