BMJ Open 3:e002321 doi:10.1136/bmjopen-2012-002321
  • Epidemiology
    • Research

Cognitive ability and educational level in relation to concussion: a population study of young men

  1. Anna Julie Frøsig
  1. Department of Psychology, University of Copenhagen, Copenhagen, Denmark
  1. Correspondence to Dr Thomas William Teasdale; tom.teasdale{at}
  • Received 7 November 2012
  • Revised 15 January 2013
  • Accepted 12 February 2013
  • Published 9 March 2013


Objectives To investigate the association of concussion with cognitive ability (CA) and educational level (EL).

Design Epidemiological—cross-linkage of national computer registers.

Setting Denmark.

Participants 130 420 young men appearing before the Danish draft board during the period 2006–2010.

Primary and secondary outcome measures CA test scores, EL and occurrence of concussion during the period 2004–2009, treated either in an A&E unit or upon admission to a hospital ward.

Results The 3067 men who had suffered a concussion had lower CAs (mean=96.5, SD=15, 95% CI 95.0 to 97.0) than the total cohort and they were lower for 1452 who were admitted to a hospital ward (mean CA=95.8, SD=15, 95% CI 95.1 to 96.6) than for 1615 who were treated only at an A&E unit (mean CA=97.1, SD=15, 95% CI 96.3 to 98.0). Multiple logistic regressions revealed that the effects for EL were stronger than those for CA. Among 127 353 men not sustaining a concussion, 48% attended a ‘gymnasium’ (sixth-form college), among men treated for a concussion at an A&E unit, this falls to 36% and among men hospitalised for a concussion to 30%. Transfer to a gymnasium, if it happens, almost invariably does so before the 18th birthday. Among 701 men suffering a concussion and admitted to a hospital department after this date, only 26% (n=182) were previously transferred to a gymnasium. Among the 804 men treated at an A&E unit after their 18th birthday, 33% (n=265) had done so. These two percentages are significantly below the corresponding non-concussed population (48%).

Conclusions Taken together, the results suggest that lower CA and, in particular, lower EL are risk factors for sustaining a concussion, the risk increasing with the severity of the injury.

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