用ROC曲线确定最佳临界点和可疑值范围

目的：使用ROC曲线法，评价某试剂盒对冠心病的诊断价值，明确针对本试剂盒的诊断临界点，并探讨用ROC曲线法确定可疑值范围。方法：根据冠脉造影结合临床确定的正常组508例和冠心病组176例测定的某血浆指标含量，绘制ROC曲线。结果：ROC曲线下面积为0．9723，并有统计学意义，说明该试剂盒有较高的诊断价值。通过ROC曲线，确定诊断临界点为40．70U／L，并具有较高的灵敏度和特异度，可疑值范围为(36．90，47．80)U／L，一致性检验结果较好。结论：使用ROC曲线评价具有简单有效，并可用来确定诊断试验的敏感度及可疑值范围。

RECEIVER OPERATING CHARACTERISTIC CURVES TO DETERMINE THE OPTIMAL OPERATING POINT AND DOUBTABLE VALUE INTERVAL

Objective:To evaluate the clinical value and discriminatory power of a diagnostic kit to diagnose Coronary Heart Disease and determine the Optimal Operating Point(OOP) using the Receiver Operating Characteristic(ROC) curves,and explore the method to determine the doubtable value interval.Methods:Based on the CAG and clinical observations,508 people with the disease and 176 without the disease were selected to measure their OxLDL,and the ROC curve was plotted.Results:The area under the curve was 0.9723 with a high statistical significance.It showed that the diagnostic kit was suitable for Coronary Heart Disease screening,the OOP of the diagnostic kit was determined and interpreted at 40.70 U/L with higher sensitivity and specificity.The doubtable value interval of 36.90 U/L to 47.80 U/L was determined at the same time.Conclusion:It was useful using ROC curve when assessing the performance and determining the OOP and doubtable value interval of a screening test.