Sex differences in concussion incidence before and during the COVID-19 pandemic: a population-based study (2017-2022).

OBJECTIVES: This population-based retrospective study investigated the impact of sex on annual case counts and incidence rates of concussions before and during COVID-19 pandemic. METHODS: Using administrative data from ICES, we identified 393,397 individuals with concussion between April 2017 and March 2022 in the Province of Ontario, Canada. A one-year washout period (no concussion/head injury diagnosis in the prior 365 days) was employed to ensure new cases. Data were stratified by sex, age groups, and rurality comparing 2019 as the pre-pandemic period to 2020 a the pandemic period. RESULTS: The pandemic led to a sharp decline in concussion rates for both sexes across all age groups. Annual case counts dropped from over 99,000 cases in pre-pandemic years to 33,693 in 2020 with the most significant reductions in school-aged children and adolescents. Despite the overall decline, the female share of diagnosed concussions increased modestly during the pandemic, with age-stratified analyses showing that sex-specific patterns varied across age groups. Poisson regression analysis revealed that females had a 16.8% higher concussion rate than males after adjusting for age and rurality. CONCLUSION: The pandemic significantly altered healthcare-recorded concussion patterns, likely reflecting both reduced exposure to injury risk and pandemic-related changes in healthcare-seeking and case capture. Our findings underscore the need to incorporate sex as a key variable in future concussion research and prevention strategies.