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

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; =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.