title: Cost-effectiveness of Ward Closure to Control Outbreaks of Norovirus Infection in United Kingdom National Health Service Hospitals.
abstract: BACKGROUND
  Norovirus is the most common cause of outbreaks of acute gastroenteritis in National Health Service hospitals in the United Kingdom. Wards (units) are often closed to new admissions to stop the spread of the virus, but there is limited evidence describing the cost-effectiveness of ward closure.
  
  
  METHODS
  An economic analysis based on the results from a large, prospective, active-surveillance study of gastroenteritis outbreaks in hospitals and from an epidemic simulation study compared alternative ward closure options evaluated at different time points since first infection, assuming different efficacies of ward closure.
  
  
  RESULTS
  A total of 232 gastroenteritis outbreaks occurring in 14 hospitals over a 1-year period were analyzed. The risk of a new outbreak in a hospital is significantly associated with the number of admission, general medical, and long-stay wards that are concurrently affected but is less affected by the level of community transmission. Ward closure leads to higher costs but reduces the number of new outbreaks by 6%-56% and the number of clinical cases by 1%-55%, depending on the efficacy of the intervention. The incremental cost per outbreak averted varies from £10 000 ($14 000) to £306 000 ($428 000), and the cost per case averted varies from £500 ($700) to £61 000 ($85 000). The cost-effectiveness of ward closure decreases as the efficacy of the intervention increases, and the cost-effectiveness increases with the timing of the intervention. The efficacy of ward closure is critical from a cost-effectiveness perspective.
  
  
  CONCLUSIONS
  Ward closure may be cost-effective, particularly if targeted to high-throughput units.
authors.affiliation: London School of Hygiene and Tropical Medicine.
authors.forename: Zia
authors.initials: Z
authors.lastname: Sadique
authors.affiliation: Public Health England, London.
authors.forename: Ben
authors.initials: B
authors.lastname: Lopman
authors.affiliation: Nuffield Department of Clinical Medicine, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, United Kingdom Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Ben S
authors.initials: BS
authors.lastname: Cooper
authors.affiliation: London School of Hygiene and Tropical Medicine.
authors.forename: W John
authors.initials: WJ
authors.lastname: Edmunds
mesh_terms: D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D003362:Cost-Benefit Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D004196:Disease Outbreaks / Q000517:prevention & control*; D005759:Gastroenteritis / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D006271:Health Facility Closure / Q000191:economics*; D006761:Hospitals; D006801:Humans; D029322:Norovirus; D006113:United Kingdom / Q000453:epidemiology
keywords: cost-effectiveness; norovirus; outbreak; ward closure