title: Is the maturity of hospitals' quality improvement systems associated with measures of quality and patient safety?
abstract: BACKGROUND
  Previous research addressed the development of a classification scheme for quality improvement systems in European hospitals. In this study we explore associations between the 'maturity' of the hospitals' quality improvement system and clinical outcomes.
  
  
  METHODS
  The maturity classification scheme was developed based on survey results from 389 hospitals in eight European countries. We matched the hospitals from the Spanish sample (113 hospitals) with those hospitals participating in a nation-wide, voluntary hospital performance initiative. We then compared sample distributions and explored associations between the 'maturity' of the hospitals' quality improvement system and a range of composite outcomes measures, such as adjusted hospital-wide mortality, -readmission, -complication and -length of stay indices. Statistical analysis includes bivariate correlations for parametrically and non-parametrically distributed data, multiple robust regression models and bootstrapping techniques to obtain confidence-intervals for the correlation and regression estimates.
  
  
  RESULTS
  Overall, 43 hospitals were included. Compared to the original sample of 113, this sample was characterized by a higher representation of university hospitals. Maturity of the quality improvement system was similar, although the matched sample showed less variability. Analysis of associations between the quality improvement system and hospital-wide outcomes suggests significant correlations for the indicator adjusted hospital complications, borderline significance for adjusted hospital readmissions and non-significance for the adjusted hospital mortality and length of stay indicators. These results are confirmed by the bootstrap estimates of the robust regression model after adjusting for hospital characteristics.
  
  
  CONCLUSIONS
  We assessed associations between hospitals' quality improvement systems and clinical outcomes. From this data it seems that having a more developed quality improvement system is associated with lower rates of adjusted hospital complications. A number of methodological and logistic hurdles remain to link hospital quality improvement systems to outcomes. Further research should aim at identifying the latent dimensions of quality improvement systems that predict quality and safety outcomes. Such research would add pertinent knowledge regarding the implementation of organizational strategies related with quality of care outcomes.
authors.affiliation: Avedis Donabedian University Institute, Autonomous University of Barcelona, Barcelona, Spain. oliver.groene@lshtm.ac.uk
authors.forename: Oliver
authors.initials: O
authors.lastname: Groene
authors.forename: Nuria
authors.initials: N
authors.lastname: Mora
authors.forename: Andrew
authors.initials: A
authors.lastname: Thompson
authors.forename: Mercedes
authors.initials: M
authors.lastname: Saez
authors.forename: Mercè
authors.initials: M
authors.lastname: Casas
authors.forename: Rosa
authors.initials: R
authors.lastname: Suñol
mesh_terms: D003430:Cross-Sectional Studies; D019538:Health Care Surveys; D006761:Hospitals / Q000145:classification / Q000592:standards*; D006801:Humans; D019300:Medical Errors / Q000517:prevention & control*; D017063:Outcome Assessment, Health Care; D011785:Quality Assurance, Health Care / Q000379:methods*; D012044:Regression Analysis; D017751:Safety Management; D013030:Spain