title: Hospital discharge abstract data on comorbidity improved the prediction of death among patients hospitalized with aspiration pneumonia.
abstract: OBJECTIVE
  To use diagnoses reported as present at admission in California hospital discharge abstract data to identify categories of comorbid disease and conditions related to aspiration pneumonia and to assess their association with hospital mortality.
  
  
  METHODS
  The study population included all persons hospitalized in California from 1996 through 1999, with a principal diagnosis of aspiration pneumonia. Present at admission diagnoses representing comorbid diseases were separated from conditions closely related to aspiration pneumonia by a physician panel through a computer supported Delphi process. Multivariable logistic regression was used to assess the probability of hospital death after adjusting for these patient characteristics. The statistical performance of this method was compared to the performance of two independent methods for measuring comorbid disease. The practical significance of differences in statistical performance was assessed by comparing the estimated effects of age, race, and ethnicity after adjustments using each method.
  
  
  RESULTS
  Mortality risk adjustment using present at admission diagnoses resulted in substantially better statistical performance and in different measurements of the adjusted effects of age, race, and ethnicity.
  
  
  CONCLUSIONS
  Reporting present at admission diagnoses in hospital discharge data yields meaningful improvements in hospital mortality risk adjustment.
authors.affiliation: Department of Health Evaluation Sciences, University of Virginia, School of Medicine, Blake Center, Room 400B, 1224 West Main Street, P.O. Box 800821, Charlottesville, VA 22908-0821, USA. gstukenborg@virginia.edu
authors.forename: George J
authors.initials: GJ
authors.lastname: Stukenborg
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Wagner
authors.forename: Frank E
authors.initials: FE
authors.lastname: Harrell
authors.forename: M Norman
authors.initials: MN
authors.lastname: Oliver
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Kilbridge
authors.forename: Jason
authors.initials: J
authors.lastname: Lyman
authors.forename: Jonathan
authors.initials: J
authors.lastname: Einbinder
authors.forename: Alfred F
authors.initials: AF
authors.lastname: Connors
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D002648:Child; D015897:Comorbidity; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010343:Patient Admission; D010351:Patient Discharge / Q000706:statistics & numerical data*; D011015:Pneumonia, Aspiration / Q000208:ethnology / Q000401:mortality*; D020379:Risk Adjustment