@article{ref1,
title="What is the risk of recurrent concussion in children and adolescents aged 5-18 years? A systematic review and meta-analysis",
journal="British journal of sports medicine",
year="2020",
author="van Ierssel, Jacqueline and Osmond, Martin and Hamid, Jemila and Sampson, Margaret and Zemek, Roger",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="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; I2=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.<p /> <p>Language: en</p>",
language="en",
issn="0306-3674",
doi="10.1136/bjsports-2020-102967",
url="http://dx.doi.org/10.1136/bjsports-2020-102967"
}