新型冠状病毒肺炎早期诊断相关因素的Logistic回归及ROC曲线分析

Logistic Regression and ROC Curve Analysis of Factors Related to the Early Diagnosis of Novel Coronavirus Pneu⁃monia

目的:分析总结COVID-19患者流行病学基本特征及常规实验室检查结果,探讨有利于COVID-19早期诊断和确诊的因素,为COVID-19早期确诊提供一定理论依据。方法:纳入我院2020年2月9日前隔离病房收治的所有疑似患者,临床资料随访至2020年3月10日。以咽拭子RT-PCR结果作为COVID-19确诊标准,比较COVID-19患者与非COVID-19患者流行病学特征及门诊或入院首次常规实验室检查结果之间的差异,并作Logis⁃tic回归分析,对具有诊断价值的指标绘制ROC曲线,运用AUC评价其预测价值。结果:共收治315例疑似患者,最终确诊COVID-19患者108例,非COVID-19患者207例。两组患者在年龄、接触史、白细胞计数、淋巴细胞计数、C-反应蛋白、血沉方面差异具有统计学意义(P<0.01),Logistic回归分析结果显示年龄、接触史、淋巴细胞下降是COVID-19具有预测价值的独立因素(P<0.05)。首次RT-PCR检测AUC为0.84(95%CI=0.73~0.89),累计2次RT-PCR检测AUC为0.92(95%CI=0.88~0.96),累计3次RT-PCR检测AUC为0.96(95%CI=0.93~0.99),首次CT具有较明显COVID-19影像学特征96例,AUC为0.74(95%CI=0.69~0.80)。患者年龄、疫区/确诊人群接触史、淋巴计数下降AUC分别为0.66(95%CI=0.60~0.73)、0.64(95%CI=0.57~0.70)、0.59(95%CI=0.53~0.66)。胸部CT联合年龄、接触史及淋巴细胞计数降低AUC为0.84(95%CI=0.72~0.90)。41.5岁为预测COVID-19的临界值,诊断敏感性0.70(95%CI=0.61~0.79),特异性0.59(95%CI=0.52~0.66),阳性似然比1.71,阴性似然比0.50。淋巴细胞记数1.53×10^(9)/L为预测COVID-19的临界值,诊断敏感性0.82(95%CI=0.73~0.88),特异性0.50(95%CI=0.43~0.57),阳性似然比1.64,阴性似然比0.37。结论:首次RT-PCR检测诊断准确性一般,假阴性率较高,累计3次以上核酸RT-PCR检测具有较高的诊断准确性。在首次RT-PCR检测阴性情况下应结合患者症状胸部CT影像学特征,若患者有疫区/确诊人群接触史、年龄大于41.5岁、淋巴细胞记数小于1.53×10^(9)/L应高度警惕SARSCoV-2感染的可能。

Objective To analyze and summarize the basic epidemiological characteristics of COVID-19 patients and the re⁃sults of routine laboratory examinations,explore the factors that are conducive to the early diagnosis and diagnosis of COVID-19,and provide a certain theoretical basis for the early diagnosis of COVID-19.Methods All suspected patients with CO⁃VID-19 admitted to the isolation ward of our hospital before February 9,2020 were included,and the clinical data were followed up to March 10,2020.The RT-PCR results of throat swabs were used as the diagnostic criteria of COVID-19.The differences in epidemiological characteristics and the first routine laboratory examination results between COVID-19 patients and non COVID-19 patients were compared,and logistic regression analysis was made.The receiver operating characteristic(ROC)curve was drawn for the indexes with diagnostic value and area under curve(AUC)was used to eval⁃uate its predictive value.Results A total of 315 suspected patients were treated,including 108 patients with COVID-19 and 207 patients without COVID-19.The two groups of patients had statistically significant differences in age,exposure history,white blood cell count,lymphocyte count,C-reactive protein and erythrocyte sedimentation rate(P<0.01).Logis⁃tic regression analysis showed that age,contact history and lymphocyte decline were independent factors with predictive val⁃ue of COVID-19(P<0.05).The AUC detected by RT-PCR was 0.84 for the first time(95%CI=0.73~0.89),and the cumulative 2 RT-PCR detection AUC was 0.92(95%CI=0.88~0.96).Accumulatively,the AUC of the three RT-PCR tests was 0.96(95%CI=0.93~0.99).The first CT had more obvious COVID-19 imaging features in 96 cases,and the AUC was 0.74(95%CI=0.69~0.80).The patient's age,contact history of the affected area/confirmed population,and decreased lymph count AUC were 0.66(95%CI=0.60~0.73),0.64(95%CI=0.57~0.70)and 0.59(95%CI=0.53~0􀆰66)respectively.The AUC of chest CT combined with age,contact history and lymphocyte count decrease was 0.84(95%CI=0.72~0.90).41.5 years old was the cut-off value for predicting COVID-19.The diagnostic sensitivity was 0.70(95%CI=0.61~0.79),and the specificity is 0.59(95%CI=0.52~0.66).The positive likelihood ratio was 1.71,and the negative likelihood ratio was 0.50.The lymphocyte count 1.53×10^(9)/L was the cut-off value for predicting COVID-19.The diagnostic sensitivity was 0.82(95%CI=0.73~0.88),and the specificity was 0.50(95%CI=0.43~0.57).The positive likelihood ratio was 1.64,and the negative likelihood ratio was 0.37.Conclusion The diagnostic accuracy of the first RT-PCR test is general,and the false negative rate is high.Accumulatively more than 3 nucleic acid RT-PCR tests have a high diagnostic accuracy.In the case of a negative RT-PCR test for the first time,the patient's symptoms and chest CT imaging characteristics should be combined.If the patient has a contact history in the epidemic area/confirmed population,the age is greater than 41.5 years old,and the lymphocyte count is less than 1.53×10^(9)/L should be highly vigilant against the pos⁃sibility of SARS-CoV-2 infection.