title: The impact of stroke unit care on outcome in a Scottish stroke population, taking into account case mix and selection bias.
abstract: OBJECTIVE
  Randomised trials indicate that stroke unit care reduces morbidity and mortality after stroke. Similar results have been seen in observational studies but many have not corrected for selection bias or independent predictors of outcome. We evaluated the effect of stroke unit compared with general ward care on outcomes after stroke in Scotland, adjusting for case mix by incorporating the six simple variables (SSV) model, also taking into account selection bias and stroke subtype.
  
  
  METHODS
  We used routine data from National Scottish datasets for acute stroke patients admitted between 2005 and 2011. Patients who died within 3 days of admission were excluded from analysis. The main outcome measures were survival and discharge home. Multivariable logistic regression was used to estimate the OR for survival, and adjustment was made for the effect of the SSV model and for early mortality. Cox proportional hazards model was used to estimate the hazard of death within 365 days.
  
  
  RESULTS
  There were 41 692 index stroke events; 79% were admitted to a stroke unit at some point during their hospital stay and 21% were cared for in a general ward. Using the SSV model, we obtained a receiver operated curve of 0.82 (SE 0.002) for mortality at 6 months. The adjusted OR for survival at 7 days was 3.11 (95% CI 2.71 to 3.56) and at 1 year 1.43 (95% CI 1.34 to 1.54) while the adjusted OR for being discharged home was 1.19 (95% CI 1.11 to 1.28) for stroke unit care.
  
  
  CONCLUSIONS
  In routine practice, stroke unit admission is associated with a greater likelihood of discharge home and with lower mortality up to 1 year, after correcting for known independent predictors of outcome, and excluding early non-modifiable mortality.
authors: Division of Applied Medicine, Department of Medicine and Therapeutics, Polwarth Building, Foresterhill, University of Aberdeen, Aberdeen, UK.
authors: Melanie
authors: M
authors: Turner
authors: Stroke Unit, Monklands General Hospital, Monkscourt Avenue, Airdrie, UK.
authors: Mark
authors: M
authors: Barber
authors: Information Services Division, NHS National Services Scotland, Edinburgh, UK.
authors: Hazel
authors: H
authors: Dodds
authors: Division of Clinical Neurosciences, University of Edinburgh, Western General Hospital, Edinburgh, UK.
authors: Martin
authors: M
authors: Dennis
authors: Academic Section of Geriatric Medicine, University of Glasgow, Royal Infirmary, Glasgow, UK.
authors: Peter
authors: P
authors: Langhorne
authors: Division of Applied Medicine, Department of Medicine and Therapeutics, Polwarth Building, Foresterhill, University of Aberdeen, Aberdeen, UK.
authors: Mary Joan
authors: MJ
authors: Macleod
mesh_terms: D000368:Aged; D002423:Cause of Death; D003953:Diagnosis-Related Groups; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D016013:Likelihood Functions; D008297:Male; D016017:Odds Ratio; D010351:Patient Discharge / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012606:Scotland; D015983:Selection Bias; D020521:Stroke / Q000401:mortality / Q000628:therapy*; D016019:Survival Analysis
keywords: Stroke