红细胞参数的运算公式对缺铁性贫血与β-地中海贫血鉴别诊断价值探讨

Evaluation of diagnostic value of discriminant indices in differential diagnosis of iron deficiency anemia and β-thalassemia trait

目的探讨红细胞参数的运算公式对缺铁性贫血与β-地中海贫血鉴别诊断的实用价值。方法使用全自动血细胞分析仪对160例缺铁性贫血和172例β-地中海贫血患者的红细胞相关参数进行检测,以文献报道的5个红细胞参数的运算公式作为缺铁性贫血与β-地中海贫血的鉴别指标,分析它们的灵敏度、特异度、假阳性率、假阴性率、阳性预测值、阴性预测值、约登指数、阳性似然比、阴性似然比、对应的ROC曲线以及曲线下面积。结果在诊断IDA时,MI、S&BI、SI、和EI灵敏度在72.5%-81.88%,但特异度较低,在22.09%-26.74%之间;S&LI特异度为62.79%,但灵敏度仅为9.38%。在诊断β-地中海贫血时结果相反。各红细胞参数运算公式的约登指数和阳性似然比都较低。ROC曲线下面积最高的S&LI仅为0.753。结论上述5个红细胞参数运算公式对IDA和β-TT的鉴别诊断效能不高。

Objective To discuss the practical value of several discriminant formulas calculated from red blood cell indices in differentiation between iron deficiency anemia（IDA） and β-thalassemia trait（β-TT）.Methods This study consists of 160 IDA cases and 172 β-TT cases.The red blood cell indices detected from Automatic Blood Cell Analyzer were used to evaluate five published discriminant formulas Sensitivity,specificity,false-positive rate,false-negative rate,positive predictive value,negative predictive value,Youden＇s Index,positive likelihood ratio,negative likelihood ratio and construction of receiver operative characteristic curves to calculate the area under the curve were calculated and analyzed for each index.Results When differentiated IDA patients from β-TT patients,MI,SBI,SI and EI showed sensitivity between 72.5%-81.88%,but their specificity showed between 22.09%-26.74% which were low;specificity of SLI was62.79%,but its sensitivity was 9.38%.The result were opposite to the detection of β-TT.Youden＇s Index and positive likelihood ratio of these formulas were dissatisfactory.SLI obtained the biggest area under the ROC curve which was only 0.753.Conclusion The five aforementioned formulas showed low efficiency for the discrimination between IDA and β-TT.