Ratio of hemoglobin to mean corpuscular volume: A new index for discriminating between iron deficiency anemia and thalassemia trait

Table 1 Complete blood count results of patients for the validation of the new index

Variables	Iron deficiency anemia (n = 65)	Thalassemia trait (n = 31)	P value
RBC (1012/L)	4.5 (0.4)	5.7 (0.6)	< 0.01
Hb (g/L)	104 (11)	115 (11)	< 0.01
HCT	34.2 (3.2)	37.3 (3.8)	< 0.01
MCV (fl)	76.2 (4.3)	65.1 (4.5)	< 0.01
MCH (pg)	23.4 (1.8)	20.7 (2.0)	< 0.01
MCHC (g/L)	305 (11)	312 (21)	0.22
RDW (%)	17.1 (3.8)	16.6 (1.9)	0.522
Platelet (109/L)	298 (72)	258 (87)	0.21
WBC (109/L)	6.03 (2.03)	7.19 (2.48)	0.16

RBC: Red blood count; Hb: Hemoglobin; HCT: Hematocrit; MCV: Mean corpuscular volume; MCH: Mean corpuscular hemoglobin; MCHC: Mean corpuscular hemoglobin concentration; RDW: Red blood cell distribution width.

Table 2 Diagnostic performance of the hemoglobin/mean corpuscular volume index in differentiating between iron deficiency anemia and thalassemia trait against gold standard diagnostic methods¹

Diagnostic parameters	TT, % (95%CI)	IDA, % (95%CI)
Sensitivity	93.5 (77.2-98.9)	78.4 (66.2-87.3)
Specificity	78.4 (66.2-87.3)	93.5 (77.2-98.9)
Accuracy	83.3 (74.5-89.6)
Youden's index	0.72
AUC	0.97 (0.93-1.00)
Kappa coefficient	0.65 (0.51-0.80)

¹α-TT was confirmed by the presence of mutations. β-TT carriers were confirmed by hemoglobin electrophoresis at pH 8.6 and HbA2 levels > 3.5%. And ferritin measurement was confirmed for iron deficiency anemia.

IDA: Iron deficiency anemia; TT: Thalassemia trait; 95%CI: 95% confidence interval; AUC: Area under the receiver operating characteristic curve.