title: The impact of comorbidity on perioperative outcomes of hip fractures in a geriatric fracture model.
abstract: BACKGROUND
  Older adults who sustain hip fractures usually have multiple coexisting medical problems that may impact their treatment and outcomes. The geriatric fracture center (GFC) provides a model of care that standardizes treatment and optimizes outcomes. The purpose of this study is to determine whether GFC patients with a higher burden of comorbidity or specific comorbidities are at risk for worsened perioperative outcomes, such as increased time to surgery (TTS), postoperative complications, and longer length of hospital stay (LOS).
  
  
  METHODS
  A total of 1077 patients aged 60 years and older who underwent surgery for a proximal femur fracture between April 15, 2005, and September 30, 2010, were evaluated. Comorbidities measured in the Charlson Comorbidity index were abstracted through chart review. Outcomes were TTS, postoperative complications, and LOS.
  
  
  RESULTS
  Most patients were white, with an average age of 85. One half lived in either a nursing home or an assisted living facility. The mean Charlson score was 3.06 and the nursing home residents had a significantly higher score compared to community dwellers (3.4 vs 2.8; P < .0001). Dementia was the most common comorbidity. There was no difference in the LOS or TTS based on Charlson score. The overall complication rate was 44% with delirium being the most common postoperative complication. Peripheral vascular disease, history of solid tumor, and peptic ulcer disease predicted delirium incidence. Charlson score predicted complication risk, with an odds ratio of 1.12 for each point increase.
  
  
  CONCLUSIONS
  Frailty and comorbidity put this hip fracture population at high risk for adverse perioperative outcomes. This study shows that in the GFC model of care the comorbidity burden did not impact the TTS and LOS but did predict postoperative complication rate.
authors.affiliation: Department of Medicine, University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: Isaura B
authors.initials: IB
authors.lastname: Menzies
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Mendelson
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Kates
authors.forename: Susan M
authors.initials: SM
authors.lastname: Friedman
keywords: comorbidity; dementia; hip fractures; model of care; perioperative outcomes