title: A retrospective cohort study to re-evaluate clinical correlates for intracranial injury in minor head injury.
abstract: BACKGROUND
  The aim of this study was to determine the Relative Risk (RR) ratios for common clinical correlates in adult patients with minor head injury in a cohort of patients in which loss of consciousness (LOC) and post-traumatic amnesia (PTA) were not the only entry criteria for CT scanning.
  
  
  METHODS
  The computerised CT request notes were reviewed on all patients who underwent a CT head scan with a minor head injury over a 1-year period (January 2009-December 2009). The clinical signs and symptoms at presentation were extracted from the request notes and the RR ratios were calculated for five clinical correlates: LOC, PTA, vomiting, nausea and headache.
  
  
  RESULTS
  456 Glasgow coma scale (GCS) 15 patients underwent CT scanning during the period January 2009-December 2009. 55 of the 456 patients had positive CT findings (12%). 270 patients (59%) of the GCS 15 cohort had neither LOC nor PTA and of this subgroup 27 had positive scans. LOC was the only clinical correlate in which the RR reached statistical significance; RR 2.0930 (95% CI 1.25 to 3.50). However, vomiting accounted for four cases, headache for four cases and nausea for no cases.
  
  
  CONCLUSIONS
  Using LOC or PTA as the principal entry criterion for CT scanning may result in a significant number of patients with traumatic intracranial injury being missed. Using a less stringent approach still achieved an acceptable CT abnormality rate.
authors.affiliation: Department of Emergency Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Sheehan
authors.forename: John S
authors.initials: JS
authors.lastname: Batchelor
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000647:Amnesia / Q000209:etiology; D006259:Craniocerebral Trauma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015600:Glasgow Coma Scale; D016489:Head Injuries, Closed / Q000175:diagnosis; D006261:Headache / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014474:Unconsciousness / Q000209:etiology; D014839:Vomiting / Q000209:etiology; D055815:Young Adult