Application of ROC cureves to assess the clinical value of capillary zone electrophoresis for screening alpha-thalassemia
Yuanqing Zhou, Ruilian Liang, Jianmin Xie, Yu-quan Liang, Jian-wei Luo, Yinghui Chen, Yun-xi Li · Guoji yiyao weisheng daobao · 2013
Objective To explore the clinical value of capillary zone electrophoresis for screening alpha-thalassemia and to ascertain the cutoff value of HbA2 for the diagnosis of alpha-thalassemia.Methods 66 alpha-thalassemia patients (alpha-thalassemia group) and 86 healthy controls (control group) were enrolled in this study.Hemoglobin capillary zone electrophoresis and detection of alpha-thalassemia gene were arried out in both groups.The receiver operating characteristic curve (ROC) was used to assess the value of HbA2 for the diagnosis of alpha-thalassemia and the cut-off value of HbA2 were ascertained.Statistical analysis was performed with the SPSS 17.0 statistical software.Results HbA2 level was (2.65 ± 0.29)％ in the control group and (2.ββ + 0.22)％ in alpha-thalassemia group,with a significant difference (P＜0.01).HbA2 level was lower in alpha-thalassemia group than in the control group.The area under receiver operating characteristic curve (AUC) of HbA2 was 0.804 (SE:0.0β5,95％ CI:0.7β6-0.872) for diagnosis of alpha-thalassemia,and the diagnostic value had significant differences (P＜0.01),with an optimal cut-off value of 2.55％.HbA2 showed a diagnostic sensitivity of 60.5％ and specificity of 89.4％.Conclusions Hemoglobin capillary zone electrophoresis for HbA2 detection is a better method for screening alpha-thalassemia at present and has a higher clinical value. Key words: ROC curves; Hemoglobin electrophoresis; Capillary zone electrophoresis; Alpha-thalassemia; Diagnosis