title: Comparative yield of positive brain computed tomography after implementing the NICE or SIGN head injury guidelines in two equivalent urban populations.
abstract: OBJECTIVE
  To compare the yield of positive computed tomography (CT) brain examinations after the implementation of the National Institute for Clinical Excellence (NICE) or the Scottish Intercollegiate Guidance Network (SIGN) guidelines, in comparable urban populations in two teaching hospitals in England and Scotland.
  
  
  METHODS
  Four hundred consecutive patients presenting at each location following a head injury who underwent a CT examination of the head according to the locally implemented guidelines were compared. Similar matched populations were compared for indication and yield. Yield was measured according to (1) positive CT findings of the sequelae of trauma and (2) intervention required with anaesthetic or intensive care unit (ICU) support, or neurosurgery.
  
  
  RESULTS
  The mean ages of patients at the English and Scottish centres were 49.9 and 49.2 years, respectively. Sex distribution was 64.1% male and 66.4% male respectively. Comparative yield was 23.8 and 26.5% for positive brain scans, 3 and 2.75% for anaesthetic support, and 3.75 and 2.5% for neurosurgical intervention. Glasgow Coma Score (GCS) <13 (NICE) and GCS ≤ 12 and radiological or clinical evidence of skull fracture (SIGN) demonstrated the greatest statistical association with a positive CT examination.
  
  
  CONCLUSIONS
  In a teaching hospital setting, there is no significant difference in the yield between the NICE and SIGN guidelines. Both meet the SIGN standard of >10% yield of positive scans. The choice of guideline to follow should be at the discretion of the local institution. The indications GCS <13 and clinical or radiological evidence of a skull fracture are highly predictive of intracranial pathology, and their presence should be an absolute indicator for fast-tracking the management of the patient.
authors.affiliation: Medical Imaging, University Hospital of North Staffordshire, City General Hospital, Stoke-on-Trent, Staffordshire, UK. ruth.summerfield@uhns.nhs.uk
authors.forename: R
authors.initials: R
authors.lastname: Summerfield
authors.forename: R
authors.initials: R
authors.lastname: Macduff
authors.forename: R
authors.initials: R
authors.lastname: Davis
authors.forename: M
authors.initials: M
authors.lastname: Sambrook
authors.forename: I
authors.initials: I
authors.lastname: Britton
mesh_terms: D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging*; D006259:Craniocerebral Trauma / Q000000981:diagnostic imaging*; D004739:England; D005260:Female; D019983:Guideline Adherence / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic / Q000592:standards*; D012606:Scotland; D014057:Tomography, X-Ray Computed; D014505:Urban Population