title: Measuring and explaining mortality in Dutch hospitals; the hospital standardized mortality rate between 2003 and 2005.
abstract: BACKGROUND
  Indicators of hospital quality, such as hospital standardized mortality ratios (HSMR), have been used increasingly to assess and improve hospital quality. Our aim has been to describe and explain variation in new HSMRs for the Netherlands.
  
  
  METHODS
  HSMRs were estimated using data from the complete population of discharged patients during 2003 to 2005. We used binary logistic regression to indirectly standardize for differences in case-mix. Out of a total of 101 hospitals 89 hospitals remained in our explanatory analysis. In this analysis we explored the association between HSMRs and determinants that can and cannot be influenced by hospitals. For this analysis we used a two-level hierarchical linear regression model to explain variation in yearly HSMRs.
  
  
  RESULTS
  The average HSMR decreased yearly with more than eight percent. The highest HSMR was about twice as high as the lowest HSMR in all years. More than 2/3 of the variation stemmed from between-hospital variation. Year (-), local number of general practitioners (-) and hospital type were significantly associated with the HSMR in all tested models.
  
  
  CONCLUSIONS
  HSMR scores vary substantially between hospitals, while rankings appear stable over time. We find no evidence that the HSMR cannot be used as an indicator to monitor and compare hospital quality. Because the standardization method is indirect, the comparisons are most relevant from a societal perspective but less so from an individual perspective. We find evidence of comparatively higher HSMRs in academic hospitals. This may result from (good quality) high-risk procedures, low quality of care or inadequate case-mix correction.
authors.affiliation: National Institute for Public Health and the Environment, Bilthoven, The Netherlands. richard.heijink@rivm.nl
authors.forename: Richard
authors.initials: R
authors.lastname: Heijink
authors.forename: Xander
authors.initials: X
authors.lastname: Koolman
authors.forename: Daniel
authors.initials: D
authors.lastname: Pieter
authors.forename: André
authors.initials: A
authors.lastname: van der Veen
authors.forename: Brian
authors.initials: B
authors.lastname: Jarman
authors.forename: Gert
authors.initials: G
authors.lastname: Westert
mesh_terms: D001509:Bed Occupancy; D003953:Diagnosis-Related Groups; D019538:Health Care Surveys; D006742:Hospital Bed Capacity; D017052:Hospital Mortality / Q000639:trends*; D006784:Hospitals, Teaching; D006801:Humans; D016015:Logistic Models; D009426:Netherlands; D010351:Patient Discharge / Q000706:statistics & numerical data; D010821:Physicians, Family / Q000600:supply & distribution; D019984:Quality Indicators, Health Care