Experimental Factor Ontology identifier EFO_0009219 (Hemoglobin F to Total Hemoglobin Ratio Measurement) is the determination of the ratio of hemoglobin F compared to total hemoglobin present in a sample. The measurement may be expressed as a ratio or percentage. [ NCI ]. Also known as: HGBFHGB, Hemoglobin F/Total Hemoglobin.