title: Does hospital performance on process measures directly measure high quality care or is it a marker of unmeasured care?
abstract: OBJECTIVE
  Quality measures may be associated with improved outcomes for two reasons. First, measured activities may directly improve care. Second, success on these measures may be a marker for other unmeasured aspects of high quality care. Our objective is to test the contribution of both possible effects.
  
  
  METHODS
  2004 Medicare data on hospital performance from Hospital Compare and risk-adjusted mortality rates from Medicare Part A claims.
  
  
  METHODS
  We studied 3,657 acute care U.S. hospitals and compared observed differences in condition-specific hospital mortality rates based on hospital performance with expected differences in mortality from the clinical studies underlying the measures.
  
  
  RESULTS
  Differences in observed mortality rates across U.S. hospitals are larger than what would be expected if these differences were due only to the direct effects of delivering measured care.
  
  
  CONCLUSIONS
  Performance measures reflect care processes that both improve care directly and are also markers of elements of health care quality that are otherwise unmeasured. This finding suggests that process measures capture important information about care that is not directly measured, and that these unmeasured effects are in general larger than the measured effects.
authors.affiliation: Center for Health Equity Research and Promotion, Philadelphia, USA.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Werner
authors.forename: Eric T
authors.initials: ET
authors.lastname: Bradlow
authors.forename: David A
authors.initials: DA
authors.lastname: Asch
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001241:Aspirin / Q000008:administration & dosage; D019985:Benchmarking; D002317:Cardiovascular Agents / Q000008:administration & dosage; D006333:Heart Failure / Q000188:drug therapy; D006739:Hospital Administration / Q000379:methods*; D017052:Hospital Mortality; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D016344:Medicare Part A / Q000706:statistics & numerical data; D009203:Myocardial Infarction / Q000188:drug therapy; D010043:Outcome and Process Assessment, Health Care / Q000458:organization & administration; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011014:Pneumonia / Q000188:drug therapy / Q000517:prevention & control; D019984:Quality Indicators, Health Care; D011787:Quality of Health Care / Q000458:organization & administration*; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D002317:Cardiovascular Agents; D022242:Pneumococcal Vaccines; D001241:Aspirin