Evaluation of sensitivity and specificity of Kerman index I and II in screening beta thalassemia minor

Background and ObjectivesBeta thalassemia minor is a common form of microcytic anemia. Although it needs no treatment, prenatal screening of beta thalassemia followed by medical counseling for prevention of birth of children with beta thalassemia major is important before marriage. The specific criterion for beta thalassemia minor diagnosis is the elevated level of Hb-A2. Some discrimination indices helpful in detection of beta thalassemia minor were reported. The aim of this study was to define the sensitivity, specificity, and Youden's index for Kerman index I and II in screening of beta thalassemia minor.Materials and MethodsA total of 82 patients with microcytic anemia (MCV< 80 fl) including 42 with beta thalassemia minor and 40 with iron deficiency anemia were selected. Differential values of Kerman index I and II were calculated; then, the sensitivity, specificity and Youden's index were evaluated. ResultsIn screening of beta thalassemia trait, sensitivity, specificity, and Youden's index were observed to be 93%, 87%, and 80% for Kerman index I respectively; for Kerman index II these figures were calculated to be 76%, 90%, and 66% in order.ConclusionsAlthough none of the discrimination indices showed complete sensitivity and specificity, but Kerman index I with higher sensitivity and specificity came out to be more valid in screening of beta thalassemia minor.