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OCTOPUS – observation or computed tomography of mild head injury in Sweden: a randomised clinical trial concerning effects and costs


Mild head injury, defined as short-term loss of consciousness and/or amnesia as a result of head trauma, is a common problem in emergency departments worldwide. Acute computed tomography (CT) in triage for admission as well as inhospital observation is suggested as standard practice for these patients. However, the outcome, safety and costs of the two strategies is unclear. To address this question a randomised controlled trial (RCT) was conducted.


A multicenter, pragmatic RCT with 39 emergency departments throughout Sweden participating to randomise the 2500 cases needed.

Eligibility criteria: Head trauma within the past 24 hours, age 6 years or older, confirmed or suspected amnesia or brief loss of consciousness, GCS 15, normal neurological findings and no associated injuries that require admission.

Randomisation: Urgent CT for all patients, early discharge for home care if normal findings. Admission for inhospital observation.

Main hypotheses : Medical outcome – the CT strategy is safe and clinically equivalent to one based on inhospital observation. Cost comparison – the CT strategy reduces costs for management of mild head injury in the acute stage. Costs in the follow-up period are equivalent between the strategies.

Endpoints: Medical outcome – patient function at 3 months (Glasgow Outcome Scale Extended). Cost comparison – resource utilisation in acute and follow-up phase.


From May 2001 through January 2004, 2603 patients underwent randomisation. Patient follow-up was completed in June 2004. Data on the primary endpoint (GOSE at 3 months) are available for 97% of the cases. Data analysis and manuscript preparation are currently under way.


The OCTOPUS study has randomised over 2600 patients with mild head injury to acute CT to triage for admission or inhospital observation. Results from the study regarding the medical effects, safety and costs of the two strategies will be available in late 2005. Data on group characteristics and practical performance will be presented at ISICEM in March 2005.

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af Geijerstam, J., Oredsson, S. & Britton, M. OCTOPUS – observation or computed tomography of mild head injury in Sweden: a randomised clinical trial concerning effects and costs. Crit Care 9, P281 (2005).

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  • Emergency Department
  • Randomise Control Trial
  • Home Care
  • Randomise Clinical Trial
  • Medical Outcome