应用ROC曲线分析C反应蛋白对下呼吸道细菌性感染的诊断价值

Diagnosis value of ROC curve analyze C reactive protein in bacterial infection in lower respiratory tract

目的 应用 ROC 曲线分析 C 反应蛋白 （ Creactiveprotein , CRP ）对下呼吸道细菌性感染中的诊断价值。方法 选取 2015 年 10 月至 2016 年 3 月我院呼吸内科住院治疗的部分呼吸系统疾病患者 152 例,分为细菌性感染组 （社区获得性肺炎—普通肺炎和重症肺炎）、特异性感染组 （结核分枝杆菌感染）、非感染组 （肺肿瘤和气胸）,对三组患者入院时治疗前检测的 CRP 、白细胞 （ WBC ）、中性粒细胞百分比 （ NEU ） % 、血沉 （ESR ）水平进行统计学分析,应用 ROC 曲线分析各指标诊断普通肺炎和重症肺炎的 ROC 曲线下的面积 （ areaundertheROCcurve , AUC ）、敏感度 （ sensitivity ,Se ）、特异度 （ specificity ,Sp）、 Youden 指数 （ Youden′sindex , YI ）,根据 CRP 的截断值评估其对下呼吸道细菌性感染诊断的敏感度和特异度。结果 ① 细菌性感染组 CRP 、 WBC 、 NEU% 、 ESR 水平均高于非感染组 （分别为 49.02±37.68vs17.99±20.96 、 10.09±6.44vs7.54±2.79 、 73.54±13.31vs64.57±9.93 、 40.55±26.30vs29.58±28.80 ）（ P ＜0.05 ）;重症肺炎组的上述指标水平均显著高于普通肺炎组 （分别为 71.34±44.35vs43.58±33.99 、 15.88±9.95vs8.67±4.27 、 82.97±11.63vs71.24±12.72 、 52.80±28.04vs37.56±25.14 ） （ P ＜0.05 ）。 ②CRP 诊断下呼吸道细菌性感染敏感度为 83.33% ,明显高于 WBC 、 NEU% 、 ESR ;普通肺炎组的 ROC 曲线显示, CRP 的 AUC=0.795 ,截断值为 12.4mg / L 时的 Se 、Sp、 YI 分别为 82.9% 、 60.6% 、 0.435 ;重症肺炎组的 ROC 曲线显示,CRP 的 AUC=0.877 , 截 断 值 为 44.7 mg / L 时 的 Se 、Sp、 YI 分 别 为 80% 、 90.9% 、 0.709 。结论 CRP 可帮助诊断下呼吸道细菌性感染,其诊断价值优于 WBC 、 NEU% 、 ESR 。 CRP＆gt;44.7mg / L对临床上早期判断重症肺炎有很好的敏感度、特异度及准确度。

Objective To discuss the value of using ROC curve to analyze CRP in patients with bacterial infection in lower respiratory tract. Methods 152 patients with respiratory diseases admitted by the department of respiratory medicine of our hospital from October 2015 to March 2016 were enrolled, they were divided into bacterial infection group （community acquired pneumonia-common pneumonia and severe pneumonia）, specific infection group （mycobacterium tuberculosis infection）, non infected group （lung cancer and pneumothorax）, to statistical analysis the level of C reactive protein （CRP）.white blood count （WBC）,Neutrophil （NEU G）,erythrocyte sedimentation rate （ESR） that tested before treatment of the three groups, the receiver operating characteristic （ROC） curve of these indexes for common pneumonia and severe pneumonia were plotted, and their diagnostic value for common pneumonia and severe pneumonia was evaluated according to area under ROC curve （AUC）, Sensitivity （Se）, Specificity （Sp） and Youdenrs index （YI）, and the sensitivity and specificity of bacterial lower respiratory tract infection were assessed based on the best diagnostic cut off point. Results ①The concentrations of CRP,WBC,NEU% ,ESR of bacterial infection group were higher than that of non-infected group（49.02 ± 37.68 vs 17.99±20.96,10.09±6.44 vs 7.54±2.79,73.54.2±13.31 vs 64.57±9.93,40.55±26.30 vs 29.58±28.80 respectively）（ P 〈0.05） ;The concentrations of these indexes of severe pneumonia group were significantly higher than that of common pneumonia group （71.34 ± 44.35 vs 43.58 ±_ 33.99,15.88± 9.95 vs8.67±4.27,82.97±11.63 vs 71.24±12.72,52.80±28.04 vs 37.56±25.14）（P〈0.05）.② The sensitivity of CRP in the diagnosis of respiratory bacterial infection diseases were 83.33%, significantly higher than WBC,NEU% （ P 〈0.05） ;The ROC curve of common pneumonia group showed that：AUC of CRP was = 0. 795, Se of 82.9%,Sp of 60.6% and YI of 0.436 with the cut-off value 12.4 mg/L;The ROC curve of severe pneumonia group showed that： AUC of CRP was=0.877, Se of 80%,Sp of 90.9% and YI of 0.709 with the cut-off value 44.7 mg/L. Conclusions CRP can help to diagnose bacterial infection in lower respiratory tract, and its diagnostic value is superior to WBC,NEU% and ESR. CRP〉44.7 mg/L has good sensitivity, specificity and accuracy in early clinical diagnosis of severe pneumonia.