Schmidt, Julianne D.Rizzone, KatherineHoffman, Nicole L.Weber, Michelle L.Jones, CourtneyBazarian, JeffBroglio, Steven P.McCrea, MichaelMcAllister, Thomas W.2018-02-162018-02-162018Schmidt, J. D., Rizzone, K., Hoffman, N. L., Weber, M. L., Jones, C., Bazarian, J., … McAllister, T. W. (2018). Age at First Concussion Influences Number of Subsequent Concussions. Pediatric Neurology. https://doi.org/10.1016/j.pediatrneurol.2017.12.017https://hdl.handle.net/1805/15230Background: Individuals that sustain their first concussion during childhood may be at greater risk for sustaining multiple concussions throughout their lifetime, due to a longer window of vulnerability. Purpose: To estimate the association between age at first concussion with number of subsequent concussions. Methods: A total of 23,582 collegiate athletes from 26 universities and military cadets from three military academies completed a concussion history questionnaire (65% males, age: 19.9±1.4years). Participants self-reported concussions and age at time of each injury. Participants with a history of concussion (n=3,647, 15.5%) were categorized as having sustained their first concussion during childhood (<10 years old - yo) or adolescence (≥10yo & ≤18yo). Poisson regression was used to model age group (childhood, adolescence) predicting number of subsequent concussions (0, 1, 2+). A second Poisson regression was developed to determine whether age at first concussion predicted number of subsequent concussions. Results: Participants self-reporting their first concussion during childhood had an increased risk of sustaining subsequent concussions (RR=2.19, 95% CI: 1.82, 2.64) compared to participants self-reporting their first concussion during adolescence. For every one-year increase in age at first concussion, we observed a 16% reduction in the risk of subsequent concussion (RR=0.84, 95% CI:0.82,0.86). Conclusion(s): Individuals self-reporting a concussion at a young age sustained a higher number of concussions prior to the age of 18. Concussion prevention, recognition, and reporting strategies are of particular need at the youth level.enPublisher Policymild traumatic brain injuryhead traumahead injuryArticle