title: What is the empirical evidence that hospitals with higher-risk adjusted mortality rates provide poorer quality care? A systematic review of the literature.
abstract: BACKGROUND
  Despite increasing interest and publication of risk-adjusted hospital mortality rates, the relationship with underlying quality of care remains unclear. We undertook a systematic review to ascertain the extent to which variations in risk-adjusted mortality rates were associated with differences in quality of care.
  
  
  METHODS
  We identified studies in which risk-adjusted mortality and quality of care had been reported in more than one hospital. We adopted an iterative search strategy using three databases--Medline, HealthSTAR and CINAHL from 1966, 1975 and 1982 respectively. We identified potentially relevant studies on the basis of the title or abstract. We obtained these papers and included those which met our inclusion criteria.
  
  
  RESULTS
  From an initial yield of 6,456 papers, 36 studies met the inclusion criteria. Several of these studies considered more than one process-versus-risk-adjusted mortality relationship. In total we found 51 such relationships in a widen range of clinical conditions using a variety of methods. A positive correlation between better quality of care and risk-adjusted mortality was found in under half the relationships (26/51 51%) but the remainder showed no correlation (16/51 31%) or a paradoxical correlation (9/51 18%).
  
  
  CONCLUSIONS
  The general notion that hospitals with higher risk-adjusted mortality have poorer quality of care is neither consistent nor reliable.
authors.affiliation: Department of Public Health and Epidemiology, University of Birmingham, Birmingham, UK. dwp@doctors.net.uk <dwp@doctors.net.uk>
authors.forename: David W
authors.initials: DW
authors.lastname: Pitches
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Mohammed
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lilford
mesh_terms: D019317:Evidence-Based Medicine; D006302:Health Services Research; D017052:Hospital Mortality; D006801:Humans; D011787:Quality of Health Care; D015203:Reproducibility of Results; D020379:Risk Adjustment