A Novel Nomogram for Predicting Pneumonia Risk in Basically Managed Rib Fracture Patients: Development and Validation

Background This study established and validated a clinical prediction model for pneumonia in patients with rib fractures receiving basic treatment. Methods This retrospective case-control study included patients with rib fractures treated at author’s hospital, between April 2017 and April 2022. The patients were randomly assigned in a 7:3 ratio to the training and validation groups. Multivariable logistic regression analysis was used to screen the independent risk factors for pneumonia. Results During the study period, 809 patients were treated for rib fractures, and 150 developed pneumonia. After LASSO selection, multivariable logistic regression analysis showed that age (OR = 1.074, 95% CI: 1.049-1.100, P < 0.001), simple hemothorax (unilateral: OR = 2.837, 95% CI: 1.399-5.754, P = 0.004), pulmonary contusion (unilateral: OR = 3.254, 95% CI: 1.695-6.250, P < 0.001), subcutaneous emphysema (mild: OR = 4.387, 95% CI: 1.871-10.287, P = 0.001), and other system damage with abbreviated injury scale (AIS) ≥3 (OR = 3.822, 95% CI: 1.536-9.512, P = 0.004) were independently associated with the occurrence of pneumonia in patients with rib fracture. The multivariable analysis was used to construct a nomogram. In the training set, the model had an area under the curve (AUC) of 0.8551 (95% CI: 0.8159-0.8942), while the AUC in the validation set was 0.8184; 95% CI: 0.7567-0.8801. Discussion This study established a model for pneumonia in patients with rib fractures based on age, simple hemothorax, pulmonary contusion, subcutaneous emphysema, and other system damage AIS ≥3. The nomogram could be used to improve patient management and identify those in need of pneumonia prevention.