title: Cost and quality implications of discrepancies between admitting and discharge diagnoses.
abstract: BACKGROUND
  Presenting and discharge diagnoses of hospitalized patients may differ as a result of patient complexity, diagnostic dilemmas, or errors in clinical judgment at the time of primary assessment. When diagnoses at admission and discharge are not in agreement, this discrepancy may indicate more complex processes of care and resultant costs. It is unclear whether surrogate measures reflecting quality of care are impacted by discrepant diagnoses.
  
  
  OBJECTIVE
  To assess whether an association exists between admitting and discharge International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes and other quality markers including hospital length of stay, total cost of care, and 30-day readmission rate.
  
  
  METHODS
  This was a retrospective, cross-sectional analysis of general internal medicine patients aged 18 years and older. Diagnosis discrepancy was defined as a difference between the 3-digit ICD-9 diagnosis code at admission and the principal 3-digit ICD-9 diagnosis code at discharge.
  
  
  RESULTS
  Sixty-eight percent of patients had a diagnosis discrepancy. Diagnosis discrepancy was associated with a 0.41-day increase in length of stay (P < .001), $663 increase in direct costs (P < .001), and a 1.55 times greater odds of readmission within 30 days (P < .001).
  
  
  CONCLUSIONS
  Diagnosis discrepancy was associated with hospital quality outcome measures. This finding likely reflects variations in patients' diagnostic complexity.
authors.affiliation: Department of Medicine, Rush University Medical Center, Chicago, Illinois 60612, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: McNutt
authors.forename: Tricia
authors.initials: T
authors.lastname: Johnson
authors.forename: Jason
authors.initials: J
authors.lastname: Kane
authors.forename: Mariel
authors.initials: M
authors.lastname: Ackerman
authors.forename: Richard
authors.initials: R
authors.lastname: Odwazny
authors.forename: Jaydeep
authors.initials: J
authors.lastname: Bardhan
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D002641:Chicago; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D017721:Hospital Costs; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D010351:Patient Discharge; D011786:Quality Control; D012189:Retrospective Studies