title: The impact of unmeasured clinical variables on the accuracy of hospital report cards: a Monte Carlo study.
abstract: OBJECTIVE
  Hospital report cards are commonly produced using administrative data. The objective of this study was to determine the impact of unmeasured clinical data on the accuracy of hospitals' report cards.
  
  
  METHODS
  Monte Carlo simulations were based on both administrative and detailed clinical data for patients hospitalized with an acute myocardial infarction in Ontario, Canada. Data were simulated such that the true performance of each hospital was known. Both clinical and administrative risk scores were randomly generated for each patient. The ability of hospital report cards to correctly identify hospitals that truly had higher than acceptable mortality was compared when both clinical and administrative data were used and when only administrative data were used. By using Monte Carlo simulations, we were able to incrementally increase the divergence between the 2 risk scores.
  
  
  RESULTS
  In a wide range of settings, sensitivity and specificity of hospital report cards was only negligibly greater when both administrative and clinical data were used compared to when only administrative data were used.
  
  
  CONCLUSIONS
  Unmeasured clinical data have at most a minor impact on the accuracy of cardiac hospital report cards.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. peter.austin@ices.on.ca
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
mesh_terms: D006739:Hospital Administration / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D009010:Monte Carlo Method; D009203:Myocardial Infarction / Q000628:therapy; D009864:Ontario; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D019984:Quality Indicators, Health Care / Q000458:organization & administration*