Article Text

Download PDFPDF

Incidence, course and risk factors of head injury: a retrospective cohort study
  1. Herman Gerritsen1,
  2. Mariam Samim2,
  3. Hans Peters2,
  4. Henk Schers2,
  5. Floris van de Laar2
  1. 1 Primary Care Center, Geert Groote Huisartsengroepspraktijk, Zwolle, The Netherlands
  2. 2 Department of Primary and Community Care, Radboud University Nijmegen Medical Centre, The Netherlands
  1. Correspondence to Dr. Floris van de Laar; Floris.vandeLaar{at}


Objectives To assess the incidence of head injury and predictors of complication across the care continuum.

Design Retrospective cohort study using data from a research network. We calculated the incidence of overall head injury in a longitudinal cohort covering 1-year interval (31 369 patient-years), and the incidence of complicated head injury in a longitudinal cohort covering 10 years interval (220 352 patient-ears). Incidence rates were calculated per 1000 patient-years with 95% CI using the Mid-P exact test. We calculated ORs to assess potential risk factors for a complicated head injury.

Setting A practice-based research network covering a population of >30 000 patients.

Participants All patients listed in practices within the research network during the years 2005–2014.

Main outcome measures Incidence of (complicated) head injury and predictors for clinical complications.

Results The incidence of overall head injury was 22.1 per 1000 person-years and the incidence of a complicated course following head injury was 0.16 per 1000 person-years. The following determinants were risk factors for a complicated course: high energy trauma, bicycle accident, traffic accident in general, use of anticoagulants, alcohol intoxication, age above 60 years and low Glasgow Coma Scale at initial presentation. A complicated course was very unlikely when the patients' first encounter with a healthcare professional was in primary care (OR 0.03, 95% CI 0.01 to 0.07).

Conclusions Complication after head injury are rarely seen in general practice. Patients who do experience complications are often easily identifiable as requiring specialist care. A more reserved referral policy for general practice may be desirable, suggesting that current guidelines are too defensive.

  • epidemiology
  • neurological injury

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors HG, MS, HP, HS, FvdL was involved and made contributions in the design of the study, acquisition, analysis and interpretation of the data. GH: drafted the work and revised it critically for important intellectual content. MS, HP, HS, FvdL: revised the work critically for important intellectual content. HG, MS, HP, HS, FvdL: gave final approval of the version published and made agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

  • Funding The Hein Hogerzeil foundation funded the article publishing fee in the form of a grant.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No data of this study are made available otherwise than in this submission.