title: Evaluating alternative risk-adjustment strategies for surgery.
abstract: BACKGROUND
  Comparison of institutional health care outcomes requires risk adjustment. Risk-adjustment methodology may influence the results of such comparisons.
  
  
  METHODS
  We compared 3 risk-adjustment methodologies used to assess the quality of surgical care. Nurse reviewers abstracted data from a continuous sample of 2,167 surgical patients at 3 academic institutions. One risk adjustor was based on medical record data (National Surgical Quality Improvement Program [NSQIP]) whereas the other 2, the DxCG and Charlson Comorbidity Index (CCI), primarily used International Classification of Disease-9 (ICD-9) codes. Risk-assessment scores from the 3 systems were compared with each other and with mortality.
  
  
  RESULTS
  Substantial disagreement was found in the risk assessment calculated by the 3 methodologies. Although there was a weak association between the CCI and DxCG, neither correlated well with the NSQIP. The NSQIP was best able to predict mortality, followed by the DxCG and CCI.
  
  
  CONCLUSIONS
  In surgical patients, different risk-adjustment methodologies afford divergent estimates of mortality risk.
authors.affiliation: Department of Health Policy and Management, Rollins School of Public Health, Emory University, 1518 Clifton Rd. N.E., Atlanta, GA 30322, USA. aather1@sph.emory.edu
authors.forename: Adam
authors.initials: A
authors.lastname: Atherly
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Fink
authors.forename: Darrell C
authors.initials: DC
authors.lastname: Campbell
authors.forename: Robert M
authors.initials: RM
authors.lastname: Mentzer
authors.forename: William
authors.initials: W
authors.lastname: Henderson
authors.forename: Shukri
authors.initials: S
authors.lastname: Khuri
authors.forename: Steven D
authors.initials: SD
authors.lastname: Culler
mesh_terms: D019317:Evidence-Based Medicine; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D011785:Quality Assurance, Health Care; D012372:ROC Curve; D020379:Risk Adjustment; D012680:Sensitivity and Specificity; D013503:Surgery Department, Hospital / Q000592:standards*; D013514:Surgical Procedures, Operative / Q000401:mortality* / Q000592:standards*; D016019:Survival Analysis; D017749:Total Quality Management; D014481:United States