Estimated age of first exposure to American football and outcome from concussion

Abstract

ObjectiveTo examine the association between estimated age of first exposure (eAFE) to American football and clinical measures throughout recovery following concussion.MethodsParticipants were recruited across 30 colleges and universities as part of the NCAA–DoD Concussion Assessment, Research and Education (CARE) Consortium. There were 294 NCAA American football players (age = 19 ± 1 years) evaluated 24–48 hours following concussion with valid baseline data and 327 (age = 19 ± 1 years) evaluated at the time they were asymptomatic with valid baseline data. Participants sustained a medically-diagnosed concussion between baseline testing and post-concussion assessments. Outcome measures included the number of days until asymptomatic, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) composite scores, Balance Error Scoring System (BESS) total score, and Brief Symptom Inventory 18 (BSI-18) sub-scores. The eAFE was defined as participant's age at the time of assessment minus self-reported number of years playing football.ResultsIn unadjusted regression models, younger eAFE was associated with lower (worse) ImPACT Visual Motor Speed (R2 = 0.031, p = 0.012) at 24–48 hours following injury and lower (better) BSI-18 Somatization sub-scores (R2 = 0.014, p = 0.038) when the athletes were asymptomatic. The effect sizes were very small. The eAFE was not associated with the number of days until asymptomatic, other ImPACT composite scores, BESS total score, or other BSI-18 sub-scores.ConclusionEarlier eAFE to American football was not associated with longer symptom recovery, worse balance, worse cognitive performance, or greater psychological distress following concussion. In these NCAA football players, longer duration of exposure to football during childhood and adolescence appears to be unrelated to clinical recovery following concussion.

Age of First Exposure to Football Is Not Associated With Later-in-Life Cognitive or Mental Health Problems

“…Four ( 9 – 11 , 20 ) of the nine studies reported no association between age of first exposure to football and later-in-life brain health problems. Moreover, in all studies of current high school and collegiate athletes, earlier age of first exposure to contact and collision sports has not been associated with worse neurocognitive functioning, subjectively-experienced symptoms, or postural control during preseason baseline testing ( 12 – 16 , 18 , 19 ), or worse clinical outcome following concussion ( 17 ). Considering the literature more broadly, separate from the issue of age of first exposure to football, results from 7 studies ( 33 – 38 ) 2 have observed that men who played high school football are not at increased risk for later-in-life neurodegenerative disease ( 36 , 37 ), and they do not report greater mental health problems in their 20s ( 33 , 34 ), during middle age 2 , or during older adulthood ( 35 , 38 ).…”

“…With time, other research groups have independently conducted 11 studies using diverse samples and methodologies, with none observing an association between earlier age of first exposure to football (or other contact and collision sports) and worse clinical or brain imaging outcomes (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). In current high school and collegiate athletes, age of first exposure was not associated with objectively measured neurocognitive functioning, subjectively-experienced symptoms, or postural control across seven highly-powered, observational studies (12-16, 18, 19).…”

“…In current high school and collegiate athletes, age of first exposure was not associated with objectively measured neurocognitive functioning, subjectively-experienced symptoms, or postural control across seven highly-powered, observational studies ( 12 – 16 , 18 , 19 ). Additionally, earlier age of first exposure to football was not associated with worse clinical outcome from concussion in a large study of current collegiate athletes ( 17 ). In a small clinical study of retired NFL players, there was no association between years of participation in pre-high school football and neurocognitive, neurological, or neuroimaging outcomes ( 9 ).…”

Age of First Exposure to Contact and Collision Sports and Later in Life Brain Health: A Narrative Review

“…Thus, if there is an association between earlier AFE and worse mental health or cognitive functioning, that association might emerge in association with aging. Nonetheless, the best available evidence suggests that, in current high school and collegiate athletes, earlier AFE to contact/collision sport is not associated with lower cognitive abilities on objective testing at baseline ( 84 , 87 , 88 , 90 , 123 ), greater physical, cognitive, or emotional symptom reporting at baseline ( 84 , 88 ), or worse clinical outcome following concussion ( 89 ).…”

“…Without an available pre-registered protocol detailing study outcomes and statistical analysis plans prior to data collection, it was/is not possible to determine selective outcome reporting and selective analytical reporting. One study (5%) was judged to be at high risk of bias due to a perceived limitation in the statistical analysis ( 89 ), and one study (5%) was considered high risk of bias due to clear evidence that data for only a subset of analyses was fully reported, and that the fully reported results were selected based on the (statistically significant) nature of the results ( 122 ).…”