Age at First Concussion Influences the Number of Subsequent Concussions

Individuals who sustain their first concussion during childhood may be at greater risk of sustaining multiple concussions throughout their lifetime because of a longer window of vulnerability. This article aims to estimate the association between age at first concussion and number of subsequent concussions. 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 ± 1.4 years). 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 (less than ten years old) or adolescence (≥10 and ≤18 years old). Poisson regression was used to model age group (childhood, adolescence) predicting the number of subsequent concussions (0, 1, 2+). A second Poisson regression was developed to determine whether age at first concussion predicted the number of subsequent concussions. Participants self-reporting their first concussion during childhood had an increased risk of subsequent concussions (rate ratio = 2.19, 95% confidence interval: 1.82, 2.64) compared with 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 (rate ratio = 0.84, 95% confidence interval: 0.82, 0.86). Individuals self-reporting a concussion at a young age sustained a higher number of concussions before age 18. Concussion prevention, recognition, and reporting strategies are of particular need at the youth level