title: Differences in mortality from coronary artery bypass graft surgery at five teaching hospitals.
abstract: OBJECTIVE
  To measure hospital- and surgeon-specific mortality rates for patients with coronary artery bypass graft (CABG) surgery and to examine possible reasons for any differences.
  
  
  METHODS
  Cohort study using hospital discharge abstracts and itemized bills.
  
  
  METHODS
  Five major teaching hospitals in Philadelphia, Pa.
  
  
  METHODS
  Consecutive sample of all 4613 patients over a 30-month period.
  
  
  METHODS
  In hospital mortality rates.
  
  
  RESULTS
  We observed differences in hospital mortality rates for patients who underwent coronary artery catheterization and CABG surgery during the same admission (diagnosis related group 106) but not for patients who underwent only CABG surgery during the admission (diagnosis related group 107). There were threefold differences in surgeon-specific mortality rates. The hospital mortality rates for coronary artery catheterization and CABG surgery during the same admission changed during the study and coincided with moves of surgeons among study hospitals. Our measures of illness severity did identify patients who were more likely to die, but differences in severity of illness did not explain differences in hospital- or surgeon-specific mortality rates. Patient mortality rates were not associated with the volume of procedures performed by individual surgeons. We found inconclusive evidence for an association with surgeons' clinical skills, and to a lesser extent, with the hospital's volume of procedures and the hospital's organization and staffing. A greater intensity of hospital services was not necessary for a lower mortality rate.
  
  
  CONCLUSIONS
  We conclude that studies of CABG mortality should examine mortality rates by diagnosis related group, collect data from more than 1 year, examine associations with surgeons' clinical skills, include information on hospital organization and staffing, and cautiously explore more efficient ways of providing care.
authors.affiliation: Section of General Internal Medicine, The Leonard Davis Institute of Health Economics, University of Pennsylvania School of Medicine.
authors.forename: S V
authors.initials: SV
authors.lastname: Williams
authors.forename: D B
authors.initials: DB
authors.lastname: Nash
authors.forename: N
authors.initials: N
authors.lastname: Goldfarb
mesh_terms: D000367:Age Factors; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000145:classification / Q000401:mortality* / Q000706:statistics & numerical data; D003953:Diagnosis-Related Groups; D005260:Female; D013502:General Surgery / Q000706:statistics & numerical data; D006753:Hospital Records; D006784:Hospitals, Teaching; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010351:Patient Discharge / Q000706:statistics & numerical data; D015143:Philadelphia / Q000453:epidemiology; D012720:Severity of Illness Index; D015996:Survival Rate