Objective: In single-institution studies, age is a risk factor for mortality after rib fracture. Sample size has limited the assessment of other risk factors. We used a national database to analyze suspected risk factors contributing to pneumonia and mortality in patients sustaining rib fractures.
Design: : Database analysis.
Patients: All patients with rib fractures discharged from hospitals submitting information to the Nationwide Inpatient Sample database.
Interventions: The 1999 Nationwide Inpatient Sample was queried for all patients with rib fracture. Age, gender, number of rib fractures, Injury Severity Score, comorbidities, pneumonia, and mortality were abstracted from the database. Comorbidities were scored according to Elixhauser. Multivariate analysis identified independent risk factors for mortality and pneumonia.
Measurements and main results: We identified 23,426 patients; 17,308 patients had a primary diagnosis of trauma and were included in the analysis. Mean age was 56. Mean Injury Severity Score was 13.1. The number of comorbidities ranged from 0 to 9. Overall mortality was 4%. Six percent of patients had pneumonia. In a multivariate model, age and Injury Severity Score were significantly associated with both mortality and pneumonia. Comorbidity score was associated with pneumonia and mortality only in patients with isolated thoracic trauma. Pneumonia was associated with mortality only in patients with isolated thoracic trauma.
Conclusions: In a model controlling for multiple known risk factors, age and Injury Severity Score were the only important predictors of mortality in patients with rib fractures and multiple-system injury. Pneumonia was significantly associated with mortality only in patients with isolated thoracic trauma.