目的 建立5岁以下儿童重症肺炎支原体肺炎（severe Mycoplasmapneumoniae pneumonia, SMPP）的预测模型。 方法 回顾性分析2023年1—12月武汉科技大学附属孝感医院收治的小于5岁的504例肺炎支原体肺炎患儿的临床资料，根据出院诊断分为非SMPP组（n=345）和SMPP组（n=159）。采用单因素分析、LASSO回归筛选SMPP的预测因子，然后纳入多因素logistic回归分析构建预测模型并评价其效能。 结果 多因素logistic回归分析显示，肺部影像学表现（实变影比例）、发热时长、超敏C反应蛋白、乳酸脱氢酶、肌酸激酶、淋巴细胞/中性粒细胞计数比值是SMPP的预测因子（P<0.05）。基于这6个指标构建的SMPP预测模型的受试者操作特征曲线下面积为0.862（95%CI：0.824~0.900），灵敏度为85.8％，特异度为77.4％。校准曲线与理想曲线接近，且Spiegelhalter的Z检验显示模型校准度良好（P=0.313）。决策曲线显示净获益阈值概率范围为0.75％~100％，说明模型临床适用性高。 结论 基于肺部影像学表现（实变影比例）、发热时长、超敏C反应蛋白、乳酸脱氢酶、肌酸激酶和淋巴细胞/中性粒细胞计数比值构建的5岁以下儿童SMPP预测模型的效能良好。

Objective To establish a predictive model for severe Mycoplasma pneumoniae pneumonia (SMPP) in children younger than 5 years. Methods Clinical data of 504 children younger than 5 years with Mycoplasma pneumoniae pneumonia admitted to Xiaogan Hospital of Wuhan University of Science and Technology from January to December 2023 were retrospectively analyzed. Based on discharge diagnosis, patients were classified into a non-SMPP group (n=345) and an SMPP group (n=159). Univariate analysis and LASSO regression were used to screen predictors of SMPP. The selected variables were then entered into a multivariable logistic regression to construct the prediction model, and its performance was evaluated. Results Multivariable logistic regression identified lung imaging findings (proportion with consolidation), duration of fever, high-sensitivity C-reactive protein, lactate dehydrogenase, creatine kinase, and lymphocyte-to-neutrophil ratio as predictors of SMPP (P<0.05). The model based on these six indicators achieved an area under the receiver operating characteristic curve of 0.862 (95%CI: 0.824-0.900), with a sensitivity of 85.8% and a specificity of 77.4%. The calibration curve was close to the ideal curve, and Spiegelhalter's Z test indicated good calibration (P=0.313). Decision curve analysis showed a net benefit across a threshold probability range of 0.75%-100%, indicating high clinical applicability. Conclusions The predictive model based on lung imaging findings (proportion with consolidation), duration of fever, high-sensitivity C-reactive protein, lactate dehydrogenase, creatine kinase, and lymphocyte-to-neutrophil ratio shows good performance for predicting SMPP in children younger than 5 years.