title: A systematic review of hospital accreditation: the challenges of measuring complex intervention effects.
abstract: BACKGROUND
  The increased international focus on improving patient outcomes, safety and quality of care has led stakeholders, policy makers and healthcare provider organizations to adopt standardized processes for evaluating healthcare organizations. Accreditation and certification have been proposed as interventions to support patient safety and high quality healthcare. Guidelines recommend accreditation but are cautious about the evidence, judged as inconclusive. The push for accreditation continues despite sparse evidence to support its efficiency or effectiveness.
  
  
  METHODS
  We searched MEDLINE, EMBASE and The Cochrane Library using Medical Subject Headings (MeSH) indexes and keyword searches in any language. Studies were assessed using the Cochrane Risk of Bias Tool and AMSTAR framework. 915 abstracts were screened and 20 papers were reviewed in full in January 2013. Inclusion criteria included studies addressing the effect of hospital accreditation and certification using systematic reviews, randomized controlled trials, observational studies with a control group, or interrupted time series. Outcomes included both clinical outcomes and process measures. An updated literature search in July 2014 identified no new studies.
  
  
  RESULTS
  The literature review uncovered three systematic reviews and one randomized controlled trial. The lone study assessed the effects of accreditation on hospital outcomes and reported inconsistent results. Excluded studies were reviewed and their findings summarized.
  
  
  CONCLUSIONS
  Accreditation continues to grow internationally but due to scant evidence, no conclusions could be reached to support its effectiveness. Our review did not find evidence to support accreditation and certification of hospitals being linked to measurable changes in quality of care as measured by quality metrics and standards. Most studies did not report intervention context, implementation, or cost. This might reflect the challenges in assessing complex, heterogeneous interventions such as accreditation and certification. It is also may be magnified by the impact of how accreditation is managed and executed, and the varied financial and organizational healthcare constraints. The strategies hospitals should impelment to improve patient safety and organizational outcomes related to accreditation and certification components remains unclear.
authors.affiliation: South-Eastern Norway Regional Health Authority, Hamar, Norway. kirsten.brubakk@helse-sorost.no.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Brubakk
authors.affiliation: Prevention, Health promotion and Organization Unit, Norwegian Knowledge Centre for the Healthcare Services, Oslo, Norway. gunn.vist@kunnskapssenteret.no.
authors.forename: Gunn E
authors.initials: GE
authors.lastname: Vist
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway. geir.bukholm@fhi.no.
authors.forename: Geir
authors.initials: G
authors.lastname: Bukholm
authors.affiliation: Wayne State University School of Medicine, Michigan, USA. pbarach@gmail.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Barach
authors.affiliation: Department of Medicine and Health, South-Eastern Norway Regional Health Authority, Hamar, Norway. ole.tjomsland@helse-sorost.no.
authors.forename: Ole
authors.initials: O
authors.lastname: Tjomsland
mesh_terms: D000068:Accreditation; D000288:Administrative Personnel; D019985:Benchmarking; D006282:Health Personnel; D006761:Hospitals / Q000592:standards*; D006801:Humans; D065186:Interrupted Time Series Analysis; D061214:Patient Safety; D011787:Quality of Health Care / Q000592:standards