title: Coronary angioplasty volume-outcome relationships for hospitals and cardiologists.
abstract: OBJECTIVE
  To assess the relationship between each of 2 provider volume measures (annual hospital volume and annual cardiologist volume) for percutaneous transluminal coronary angioplasty (PTCA) and 2 outcomes of PTCA (in-hospital mortality and same-stay coronary artery bypass graft [CABG] surgery).
  
  
  METHODS
  Cohort study, using data from January 1, 1991, through December 31, 1994, from the Coronary Angioplasty Reporting System of the New York State Department of Health.
  
  
  METHODS
  Thirty-one hospitals in New York State in which PTCA was performed during 1991-1994.
  
  
  METHODS
  All 62670 patients discharged after undergoing PTCA in these hospitals during 1991-1994.
  
  
  METHODS
  Rates of in-hospital mortality and CABG surgery during the same stay as the PTCA.
  
  
  RESULTS
  The overall in-hospital mortality rate for patients undergoing PTCA in New York during 1991-1994 was 0.90%, and the same-stay CABG surgery rate was 3.43%. Patients undergoing PTCA in hospitals with annual PTCA volumes less than 600 experienced a significantly higher risk-adjusted in-hospital mortality rate of 0.96% (95% confidence interval [CI], 0.91%-1.01%) and risk-adjusted same-stay CABG surgery rate of 3.92% (95% CI, 3.76%-4.08%). Patients undergoing PTCA by cardiologists with annual PTCA volumes less than 75 had mortality rates of 1.03% (95% CI, 0.91%-1.17%) and same-stay CABG surgery rates of 3.93% (95% CI, 3.65%-4.24%); both of these rates were also significantly higher than the rates for all patients. Also, same-stay CABG surgery rates for patients undergoing PTCA in hospitals with annual volumes of 600 to 999 performed by cardiologists with annual volumes of 75 to 174 (2.99%; 95% CI, 2.69%-3.31 %) and 175 or more (2.84%; 95% CI, 2.57%-3.14%) were significantly lower than the overall statewide rate (3.43%).
  
  
  CONCLUSIONS
  In New York State, both hospital PTCA volume and cardiologist PTCA volume are significantly inversely related to in-hospital mortality rate and same-stay CABG surgery rate for patients undergoing PTCA.
authors.affiliation: State University of New York at Albany, 12144-3456, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Hannan
authors.forename: M
authors.initials: M
authors.lastname: Racz
authors.forename: T J
authors.initials: TJ
authors.lastname: Ryan
authors.forename: B D
authors.initials: BD
authors.lastname: McCallister
authors.forename: L W
authors.initials: LW
authors.lastname: Johnson
authors.forename: D T
authors.initials: DT
authors.lastname: Arani
authors.forename: A D
authors.initials: AD
authors.lastname: Guerci
authors.forename: J
authors.initials: J
authors.lastname: Sosa
authors.forename: E J
authors.initials: EJ
authors.lastname: Topol
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000401:mortality / Q000706:statistics & numerical data*; D016507:Cardiology Service, Hospital / Q000592:standards / Q000706:statistics & numerical data*; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D005260:Female; D006302:Health Services Research; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009518:New York / Q000453:epidemiology; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data*; D012307:Risk Factors