开发一款用于指导临床准确评估儿童腺病毒肺炎严重程度的列线图模型，并进行验证。

采用回顾性、横断面临床观察法，纳入2019年8月至2021年8月于徐州医科大学附属徐州儿童医院诊断为腺病毒肺炎患儿共128例为研究对象，均符合儿童腺病毒性肺炎诊断和治疗指南（2019版）的标准；住院期间参照社区获得性肺炎诊断标准分为重症组（50例）和非重症组（78例），比较两组患儿的性别、年龄、体重、是否早产、发热持续时间、体温峰值、有无基础疾病、血清白细胞计数、中性粒细胞和淋巴细胞百分比、C-反应蛋白（CRP）、乳酸、白细胞介素（IL）-6、乳酸脱氢酶（LDH）、降钙素原（PCT）、CD4⁺ T和CD8⁺ T淋巴细胞百分比、CD4⁺/CD8⁺ T、CD16⁺CD56⁺和CD19⁺ T淋巴细胞百分比、有无混合感染。采用LASSO回归法对危险因素进行降维处理，采用多因素Logistic回归分析筛选独立危险因素，根据回归系数（β）绘制列线图预测模型。采用受试者工作曲线（ROC）计算模型预测重症腺病毒肺炎（SAP）曲线下面积（AUC），Hosmer-Lemeshow检验评估模型的拟合优度，Calibration曲线和Decision曲线评估模型的一致性和获益性。

与非重症组比较，重症组患儿发热持续时间延长[5.2（3.0，8.5）d vs. 2.9（1.0，5.0）d：Z = 8.326、P < 0.001]、IL-6 [45.6（35.4，56.9） pg/ml vs. 30.2（25.2，38.6） pg/ml：Z = 15.326，P < 0.001]和LDH水平[452.6 （385.6，523.4）U/L vs. 365.9（302.1，445.2）U/L：Z = 9.625、P < 0.001]升高、CD4⁺ T [31.2（27.8，34.2）% vs. 35.5（33.2，38.9）%：Z = 7.526，P < 0.001]和CD4⁺/CD8⁺ T水平[1.2（1.0，1.4）vs. 1.4（1.1，1.6）：Z = 5.230、P = 0.004]下降、混合感染率增多[46.0%（23/50）vs. 19.2%（15/78）：χ² = 10.460、P = 0.001]。LASSO回归共筛选出4个具有非零系数特征的变量，即发热持续时间、IL-6浓度、CD4⁺ T淋巴细胞百分比和混合感染。多因素Logistic回归分析显示，发热持续时间（OR = 3.125、95%CI：2.565~3.896、P < 0.001）、IL-6浓度（OR = 2.012，95%CI：1.428~2.639、P < 0.001）、CD4⁺ T淋巴细胞百分比（OR = 0.369、95%CI：0.124~0.678、P = 0.009）和混合感染（OR = 1.457、95%CI：1.124~1.895，P = 0.001）均为SAP的独立危险因素。建立列线图模型总分160分，ROC显示列线图预测SAP的AUC值为0.852（95%CI：0.779~0.901，P < 0.001）。Hosmer-Lemeshow检验值为0.786，提示模型拟合优度较高。Calibration曲线和Decision曲线显示模型一致性和获益性尚可。

影响儿童腺病毒肺炎严重程度的主要因素有发热持续时间、IL-6浓度、CD4⁺ T淋巴细胞百分比和混合感染，以此开发的列线图预测模型来评估SAP，操作简单、可视化效果强，有较高的效能和拟合优度，一致性和获益性尚好，具有较好的临床应用价值。

To develop a nomogram model for guiding clinical accurate evaluation on the severity of adenovirus pneumonia in children, and carry out the internal validation.

Total of 128 children with adenoviral pneumonia diagnosis in Xuzhou Children’s Hospital Affiliated to Xuzhou Medical University from August 2019 to August 2021 were included, retrospectively, who all met the criteria of the guideline for the diagnosis and treatment of adenoviral pneumonia in children (2019 Edition). During hospitalization, according to the diagnostic criteria of community-acquired pneumonia, 128 cases were divided into severe group (50 cases) and non-severe group (78 cases). The gender, age, weight, premature delivery, duration of fever, peak body temperature, basic diseases, serum leukocyte count, percentage of neutrophils and lymphocytes, C-reactive protein (CRP), lactic acid, interleukin (IL)-6, lactate dehydrogenase (LDH), procalcitonin (PCT), percentage of CD4⁺ T and CD8⁺ T lymphocytes, CD4⁺/CD8⁺, CD16⁺CD56⁺ and CD19⁺ T lymphocytes, and mixed infection were compared between the two groups. The dimension of risk factors was reduced by LASSO regression, then the independent risk factors were screened by multivariate Logistic regression analysis, nomogram predictive model was drawn according to the regression coefficient (β). The area under the curve (AUC) of model for severe adenovirus pneumonia (SAP) prediction was calculated by receiver operating curve (ROC), and the goodness of fit of the model was evaluated by Hosmer-Lemeshow test, consistency and benefit of the model were evaluated by calibration curve and decision curve.

Compared with non-severe group, Univariate comparison showed that the duration of fever was longer [5.2 (3.0, 8.5) d vs. 2.9 (1.0, 5.0) d; Z = 8.326, P < 0.001], concentrations of IL-6 [45.6 (35.4, 56.9) pg/ml vs. 30.2 (25.2, 38.6) pg/ml; Z = 15.326, P < 0.001] and LDH were higher [452.6 (385.6, 523.4) U/L vs. 365.9 (302.1, 445.2) U/L; Z = 9.625, P < 0.001], levels of CD4⁺ T [31.2 (27.8, 34.2)% vs. 35.5 (33.2, 38.9)%; Z = 7.526, P < 0.001] and CD4⁺/CD8⁺ were lower [1.2 (1.0, 1.4) vs. 1.4 (1.1, 1.6); Z = 5.230, P = 0.004], and the rate of mixed infection was higher in severe group [46.0% (23/50) vs. 19.2% (15/78); χ² = 10.460, P = 0.001]. LASSO regression screened four variables with non-zero coefficients, namely duration of fever, IL-6 concentration, CD4⁺ T lymphocyte percentage and mixed infection. Multivariate Logistic regression analysis showed that duration of fever (OR = 3.125, 95%CI: 2.565-3.896, P < 0.001), IL-6 concentration (OR = 2.012, 95%CI: 1.428-2.639, P < 0.001), CD4⁺ T lymphocyte percentage (OR = 0.369, 95%CI: 0.124-0.678, P = 0.009) and mixed infection (OR = 1.457, 95%CI: 1.124-1.895, P = 0.001) were the independent risk factors for SAP. The total score of nomogram model was 160. ROC showed that the AUC value of nomogram for predicting SAP was 0.852 (95%CI: 0.779-0.901, P < 0.001). The Hosmer-Lemeshow test value was 0.786, suggesting that the goodness of fit of the model was high. The calibration curve and decision curve showed that the consistency and benefit of the model were acceptable.

The main factors affecting the severity of adenovirus pneumonia in children are the duration of fever, the concentration of IL-6, the percentage of CD4⁺ T lymphocytes and mixed infection. The developed nomogram prediction model to evaluate SAP has simple operation and strong visualization effect. It has high efficacy and goodness of fit, good consistency and benefit, and has good clinical application value.