Utility of providing a concussion definition in the assessment of concussion history in former NFL players

ABSTRACT

Objective: Former National Football League (NFL) players’ working knowledge of concussion has not yet been evaluated, despite this population being a major clinical research target due to the association between repetitive head impacts (RHI) and long-term clinical impairments. This study examined former NFL players’ understanding of the current concussion definition, and the association between number of concussions with clinical function.

Methods: 95 former NFL players (mean age = 55.29; mean NFL year = 8.10) self-reported number of concussions before being provided with a concussion definition and after being read a modern definition of concussion. Subjects reported number of concussions with loss of consciousness (LOC). Principal Component Analysis of a battery of tests generated behaviour/mood, psychomotor speed/executive function, and verbal and visual memory factor scores.

Results: Post-definition number of concussions (median = 50) was five times the pre-definition (median = 10; p < 0.001). Greater pre- (p = 0.019) and post-definition concussions (p = 0.036) correlated with worse behaviour/mood scores, after controlling for years of football played, with specific effects for depressive symptoms and impulsivity. LOC did not account for variance beyond number of concussions.

Conclusions: Practitioners and clinical researchers should provide a definition of concussion in the assessment of concussion history in former football players to facilitate accuracy and standardization.

KEYWORDS:

• American football
• concussion knowledge
• depression
• impulsivity
• mild traumatic brain injury

Acknowledgments

There are no acknowledgments to report.

Declaration of interest

Robert A. Stern has received research funding from Avid Radiopharmaceuticals, Inc. (Philadelphia, PA, USA). He is a member of the Mackey-White Committee of the NFL Players Association. He is a paid consultant to Avanir Pharmaceuticals, Inc. (Aliso Viejo, CA) and Biogen (Cambridge, MA). He receives royalties for published neuropsychological tests from Psychological Assessment Resources, Inc. (Lutz, FL, USA), as well as compensation from expert legal opinion. Robert C. Cantu is a paid consultant to the NFL Head Neck and Spine Committee, and NOCSAE. He receives royalties from book publications, and compensation from expert legal opinion. Christopher Nowinski is an unpaid member of NFL Players Association Mackey-White Committee and serves or has recently served in volunteer advisory roles for Major League Lacrosse, the NCAA and the Ivy League. He serves as president of the Concussion Legacy Foundation. He receives speaking honoraria and travel reimbursements for educational lectures. Christine Baugh has received research funding from the National Collegiate Athletic Association and the Harvard Football Players Health Study which is funded by the National Football League Players’ Association. For the remaining authors, there are no conflicts of interest to declare.

This work was supported by grants from the NIH (P30 AG13846; R01 NS 078337; R56 9500304025; U01 NS093334). This publication was also supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through BU-CTSI Grant Number 1UL1TR001430. Michael L. Alosco and research reported in this publication is supported by the National Institutes of Health under grant number 1F32NS096803-01. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Christine Baugh is currently supported by the National Institutes of Mental Health under award number T32MH019733.