title: Regional variation in hospital mortality and 30-day mortality for injured Medicare patients.
abstract: BACKGROUND
  We sought to evaluate how survival of older patients with injuries differs by geographic region within the United States.
  
  
  METHODS
  We analyzed Medicare fee-for-service records for patients aged 65 years and older with principal injury diagnoses (ICD-9 800-959, excluding 905, 930-939, 958). Cases were classified by Maximum Abbreviated Injury Score (AISmax) and Charlson Comorbidity score (0, 1, 2, >or=3). Hospital mortality and 30-day mortality were modeled as functions of age, sex, AISmax, comorbidity, and geographic region (northeast, midwest, south, west).
  
  
  RESULTS
  Hospital and 30-day mortality were both higher with male sex and increased age, AISmax, or Charlson score. Adjusted hospital mortality was highest in the northeast and south, but 30-day adjusted mortality was lowest in the same two regions.
  
  
  CONCLUSIONS
  Regional differences in risk-adjusted hospital survival for older patients with injuries are different from regional differences in 30-day survival. Hospital mortality as an outcome for older injured patients should be interpreted cautiously.
authors.affiliation: Department of Surgery, Maine Medical Center, 22 Bramhall Street, Portland, ME 04102, USA.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Gorra
authors.forename: David E
authors.initials: DE
authors.lastname: Clark
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Mullins
authors.forename: Michael A
authors.initials: MA
authors.lastname: Delorenzo
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D020379:Risk Adjustment; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000401:mortality