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Immediate computed tomography or admission for observation after mild head injury: cost comparison in randomised controlled trial

BMJ 2006; 333 doi: (Published 31 August 2006) Cite this as: BMJ 2006;333:469
  1. Anders Norlund, health economist3,
  2. Lars-Åke Marké, health economist3,
  3. Jean-Luc af Geijerstam, researcher ({at},
  4. Sven Oredsson, head of emergency department2,
  5. Mona Britton, senior medical adviser OCTOPUS Study3
  1. 1 Department of Medicine, Clinical Epidemiology Unit, Karolinska University Hospital, 171 76 Stockholm, Sweden
  2. 2 Emergency Department, Helsingborg Hospital, Helsingborg, Sweden
  3. 3 Swedish Council on Technology Assessment in Health Care, Stockholm, Sweden
  1. Correspondence to: J-L af Geijerstam
  • Accepted 22 June 2006


Objective To compare the costs of immediate computed tomography during triage for admission with those of observation in hospital in patients with mild head injury.

Design Prospective cost effectiveness analysis within a multicentre, pragmatic randomised trial.

Setting 39 acute hospitals in Sweden

Participants 2602 patients (aged ≥ 6) with mild head injury.

Interventions Immediate computed tomography or admission for observation.

Main outcome measures Direct and indirect costs related to the mild head injury during the acute and three month follow-up period.

Results Outcome after three months was similar for both strategies (non-significantly in favour of computed tomography). For the acute stage and complications, the cost was 461 euros (£314, $582) per patient in the computed tomography group and 677 euros (£462, $854) in the observation group; an average of 32% less in the computed tomography group (216 euros, 95% confidence interval −272 to −164; P < 0.001). Sensitivity analysis showed that computed tomography was the most cost effective strategy under a broad range of assumptions. After three months, total costs were 718 euros and 914 euros per patient—that is, 196 euros less in the computed tomography group (- 281 to - 114; P < 0.001). The lower cost of the computed tomography strategy at the acute stage thus remained unchanged during follow-up.

Conclusion Patients with mild head injury attending an emergency department can be managed more cost effectively with computed tomography rather than admission for observation in hospital.

Trial registration ISRCTN81464462 [].


  • Embedded ImageThe details of investigators, committee members, and other study personnel are on

  • Contributors MB, J-LG, and SO designed the study with contribution of AN and LÅM as regards economical factors. MB, J-LG, and SO applied for funding. J-LG was project coordinator. AN and MB prepared the first draft of the paper. All authors contributed to the interpretation of results and improvements of the manuscript. MB and J-LG are guarantors.

  • Funding County Council of Stockholm (Department of Research, Development, and Education); Thelma Zoéga Foundation; Apoteket; Swedish Research Council; Gorthon Foundation; Vårdal Foundation (the Swedish Foundation for Health Care Sciences and Allergy Research); Health Research Council of Southeast Sweden; Health and Medical Care Executive Board of the Region Västra Götaland; Swedish Society of Medicine; Region Skåne; and SBU (Swedish Council on Technology Assessment in Health Care).

  • Competing interests None declared.

  • Ethical approval The study was approved by all regional ethics committees in Sweden.

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