Diagnostic Significance of Red Cell Indices in Non-anemic Iron Deficiency and Iron Deficiency Anemia: Reevaluation with ROC Curve

ABSTRACT

To validate the diagnostic significance of red cell indices in non-anemic iron deficiency and iron deficiency anemia, complete blood count, serum iron, total iron binding capacity, and serum ferritin were measured in 208 middle school girls between 13 and 15 years of age. We used Reciever Operatin Characteristic (ROC) curve to compare the diagnostic significances of various red cell indices (MCV, MCH, MCHC, RDW). We also established the ideal cutoff values of red cell indices for the diagnosis of iron deficiency anemia. The results were as follows: 1) The prevalence of iron deficiency anemia and non-anemic iron deficiency were 4.8% and 11.1% respectively. 2) For the diagnosis of iron deficiency anemia, MCV had the highest diagnostic capacity, and MCH was the secondly useful one. 3) For the diagnosis of non-anemic iron deficiency. MCV had the highest diagnostic capacity, but the sensitivity and specificity of the 4 red cell indices(MCV, MCH, MCHC, RDW) were so low that they could not be used as screening or confirmative tests. 4) The sensitivity and specificity of MCV were 1 for the diagnosis of iron deficiency anemia(cutoff value: MCV=79 fl). In case of MCH, the sensitivity was. 1 and the specificity was 0.995 for the diagnosis of iron deficiency anemia(cutoff value: MCH=25pg). In case of MCHC, the sensitivity was 1 and the specificity was 0.69 for the diagnosis of iron deficiency anemia (cutoff value: MCH-33g/dl). In case of RDW, the sencitivity was 0.9 and the specificity was 0.96 for the diagnosis of iron deficiency anemia(cutoff value: RDW=13.5%). With above results, we could conclude that MCV and MCH were very useful screening tests for iron deficiency anemia and MCV could be used as a confirmative test of iron deficiency anemin.