title: Rib fractures: relationship with pneumonia and mortality.
abstract: 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.
  
  
  METHODS
  : Database analysis.
  
  
  METHODS
  All patients with rib fractures discharged from hospitals submitting information to the Nationwide Inpatient Sample database.
  
  
  METHODS
  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.
  
  
  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.
authors.affiliation: Department of Surgery, Injury Research Center, Medical College of Wisconsin, USA.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Brasel
authors.forename: Clare E
authors.initials: CE
authors.lastname: Guse
authors.forename: Peter
authors.initials: P
authors.lastname: Layde
authors.forename: John A
authors.initials: JA
authors.lastname: Weigelt
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000209:etiology* / Q000401:mortality; D012189:Retrospective Studies; D012253:Rib Fractures / Q000150:complications / Q000401:mortality*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D015599:Trauma Severity Indices