What is the risk of recurrent concussion in children and adolescents aged 5-18 years? A systematic review and meta-analysis

Br J Sports Med. 2021 Jun;55(12):663-669. doi: 10.1136/bjsports-2020-102967. Epub 2020 Oct 19.


Objective: We aimed to examine the risk of concussion in children with a previous history of concussion.

Design: Systematic review and meta-analysis. The primary outcome was number of children with and without a previous lifetime history of concussion who sustained a diagnosed concussion within each study period. Risk of bias was assessed using the Newcastle-Ottawa Scale. A random effects model was used to estimate a pooled risk ratio (RR) with corresponding 95% CIs; results were summarised in forest plots.

Data sources: Four electronic databases (MEDLINE, Embase, CINAHL, SPORTDiscus) and selected reference lists were searched (PROSPERO registration No CRD42019135462).

Eligibility criteria: Original English language peer-reviewed publications that compared concussion risk in children aged 5-18 years with and without a previous concussion history in which risk estimates were reported or able to be calculated.

Results: Of 732 identified studies, 7 studies representing 23 411 children (risk of bias range, 7-9; maximum possible score=9) were included for meta-analysis. Pooled risk of sustaining a concussion was more than three times greater in children with a previous concussion compared with those with no previous concussion (RR=3.64; 95% CI: 2.68 to 4.96; p<0.0001; I 2=90.55%). Unreported sex-stratified data precluded direct comparison of concussion risk in male versus female athletes.

Conclusion: Previously concussed children have four times the risk of sustaining a concussion compared with those with no previous concussion history. This should be a consideration for clinicians in return to sport decision-making. Future studies examining subsequent recurrent concussion in youth sports must consider sex differences.

Keywords: children; concussion; recurrent; risk factor; sporting injuries.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adolescent
  • Bias
  • Brain Concussion / etiology*
  • Child
  • Child, Preschool
  • Confidence Intervals
  • Disease Susceptibility
  • Female
  • Humans
  • Male
  • Prospective Studies
  • Recurrence
  • Retrospective Studies
  • Return to Sport*
  • Risk Assessment / methods
  • Sex Factors