Mortality after rib fracture: A population-based analysis

Abstract

Background. 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 mortality in patients sustaining rib fracture. Methods. The 1999 Nationwide Inpatient Sample was queried for all patients with rib fracture. Age, gender, number of rib fractures, ISS, comorbidities, pneumonia, and mortality were abstracted from the database. Comorbidities were scored according to Elixhauser. Multivariate analysis identified independent risk factors for mortality. Results. 23,426 patients were identified. Mean age was 59. Median number of ribs fractured was 3. Mean ISS was 11.1. The number of comorbidities ranged from 0 to 10 and 9% of patients had pneumonia. Overall mortality was 4%. Odds ratios for death are shown. Conclusions. In a model controlling for multiple known risk factors, age and injury severity are the most important predictors of mortality in patients with rib fractures. The effect of a single comorbidity is minimal; however, multiple comorbidities can increase the odds of mortality equivalent to advanced age or severe injury. TABLE—ABSTRACT 39 Risk factor Odds ratio 95% Confidence interval Age < 55 1.0 — 55–64 1.9 1.4, 2.5 65–79 2.7 2.2, 3.3 >79 5.3 4.2, 6.6 Comorbidity score ∗ 1.14 1.1, 1.2 ISS <9 1.0 — 9–15 1.4 1.2, 1.7 16–25 2.8 2.2, 3.6 >25 16.9 13.4, 21.3 Pneumonia 1.5 1.2, 1.9 Female gender 0.6 0.5, 0.7 ∗ The odds ratio for comorbidity indicates the odds ratio/comorbidity; the reference is a comorbidity score of 0 (no comorbidities).