title: Risk factors for unplanned readmissions in older adult trauma patients in Washington State: a competing risk analysis.
abstract: BACKGROUND
  Hospital readmission is a significant contributor to increasing health care use related to caring for older trauma patients. This study was undertaken with the following aims: determine the proportion of older adult trauma patients who experience unplanned readmission, as well as risk factors for these readmissions and identify the most common readmission diagnoses among these patients.
  
  
  METHODS
  We conducted a retrospective cohort study of trauma patients age 55 years and older who survived their hospitalization at a statewide trauma center between 2009 and 2010. Linking 3 statewide databases, nonelective readmission rates were calculated for 30 days, 6 months, and 1 year after index discharge. Competing risk regression was used to determine risk factors for readmission and account for the competing risk of dying without first being readmitted. Subhazard ratios (SHR) are reported, indicating the relative risk of readmission by 30 days, 6 months, and 1 year.
  
  
  RESULTS
  The cumulative readmission rates for the 14,536 participants were 7.9%, 18.9%, and 25.2% at 30 days, 6 months, and 1 year, respectively. In multivariable models, the strongest risk factors for readmission at 1 year (based on magnitude of SHR) were severe head injury (adjusted SHR = 1.47; 95% CI, 1.24-1.73) and disposition to a skilled nursing facility (SHR = 1.54; 95% CI, 1.39-1.71). The diagnoses most commonly associated with readmission were atrial fibrillation, anemia, and congestive heart failure.
  
  
  CONCLUSIONS
  In this statewide study, unplanned readmissions after older adult trauma occurred frequently up to 1 year after discharge, particularly for patients who sustained severe head trauma and who could not be discharged home independently. Examining common readmission diagnoses might inform the development of interventions to prevent unplanned readmissions.
authors.affiliation: Harborview Injury Prevention and Research Center, Seattle, WA; Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA. Electronic address: vfawcett@mac.com.
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Fawcett
authors.affiliation: Harborview Injury Prevention and Research Center, Seattle, WA; Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA.
authors.forename: Katherine T
authors.initials: KT
authors.lastname: Flynn-O'Brien
authors.affiliation: Washington State Department of Health, Seattle, WA.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Shorter
authors.affiliation: Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA.
authors.forename: Giana H
authors.initials: GH
authors.lastname: Davidson
authors.affiliation: Harborview Injury Prevention and Research Center, Seattle, WA; Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA.
authors.forename: Eileen
authors.initials: E
authors.lastname: Bulger
authors.affiliation: Harborview Injury Prevention and Research Center, Seattle, WA; Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA; Department of Pediatrics and Epidemiology, Harborview Medical Center/University of Washington, Seattle, WA.
authors.forename: Frederick P
authors.initials: FP
authors.lastname: Rivara
authors.affiliation: Harborview Injury Prevention and Research Center, Seattle, WA; Department of Surgery, Harborview Medical Center/University of Washington, Seattle, WA.
authors.forename: Saman
authors.initials: S
authors.lastname: Arbabi
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014861:Washington; D014947:Wounds and Injuries / Q000628:therapy*