Systematic Review and Meta-Analysis of Sex-Based Differences in Recurrent Concussion Incidence Across Sports

BACKGROUND: Disparities in concussion incidence exist on the basis of sex. This meta-analysis aimed to summarize the evidence for recurrent concussion incidence between male and female athletes across various sports.
METHODS:  Systematic review and meta-analysis. Data Sources - PubMed, EMBASE, and Cochrane Library databases. Eligibility Criteria for Selecting Studies - Studies written in English containing sex comparisons of recurrent concussion data published between January 2000 and June 2021 were included.
RESULTS:  A total of 1,509 records were identified, of which 114 studies were assessed for eligibility with full-text review. Six studies were ultimately included. Women were found to have more recurrent concussions than men across all sex-comparable sports, which included soccer, basketball, and baseball/softball [RR=2.16 (95% CI: 1.09-4.30)]. More specifically, women were found to have more recurrent concussions in soccer [RR=3.01 (95% CI: 2.08-4.35)] and basketball [RR=2.68 (95% CI: 1.39-5.17)], but inconclusive results were seen for baseball/softball [RR=2.54 (95% CI: 0.54-11.94)].
CONCLUSION: Recurrent concussion rates are greater in sex-comparable women’s sports than in men’s sports. Not all sports had sufficient evidence for inclusion in the meta-analysis. There are sex differences in recurrent concussion incidence in soccer and basketball.