The stability of self-reported professional football concussion history among former players: A longitudinal NFL-LONG study

ABSTRACT

Objectives

To examine the stability of former National Football League (NFL) players’ recall of professional football concussion.

Methods

Two-hundred-and-nine former NFL players (ceasing football participation before/in 2001) completed surveys in 2001, 2010, and 2019 and reported the number of concussions sustained during their professional careers (0, 1 … 10, >10). Participants were categorized into four ‘recall stability’ groups, based upon concussion recall [e.g., ‘Same’ (same number recalled), ‘Increased’ (more recalled than in prior time point)]. In 2019, participants completed measures of functioning (e.g., PROMIS Cognitive Function, Anxiety, Depression). Fleiss Kappa and generalized linear mixed models (GLMM)-based ordinal measures Kappa assessed stability across time points. ‘Recall stability group’ functioning scores were compared.

Results

Overall, 45.9% recalled more concussions over time; 14.8% reported the same number. Fleiss Kappa and GLMM-based ordinal measures Kappa suggested fair (0.22, 95% CI: 0.26, 0.38) and moderate stability (0.41, 95% CI: 0.35, 0.46), respectively. Higher cognitive functioning (P = 0.002), lower anxiety (P = 0.003), and lower depression (P = 0.007) were observed in the ‘Same’ vs ‘Increased’ groups.

Conclusions

Despite subtle time-based variations in reporting, professional football concussion history recall was relatively stable. Better cognitive and psychological functioning was associated with greater stability in concussion recall.

KEYWORDS:

• Reliability
• traumatic brain injury
• observational
• cohort

Acknowledgments

The authors are grateful to Candice Goerger, Caprice Hunt, Hope Campbell, Greggory Kobelski, Danielle Hunt, Becky Parmeter, and Alexa Wild for their invaluable efforts in the administration, coordination, and execution of the NFL-LONG study. We also thank the members of the NFL Alumni Association and Legends community for their assistance in recruitment of study participants. Last, we would like to thank each of the clinicians, researchers, educators, and former players who helped us adapt and develop the current general health survey.

Disclosure statement

ZYK reports grants from the National Football League (NFL) during the conduct of this study as well as grants from the Centers for Disease Control and Prevention (CDC), U.S. Department of Defense (DoD), and National Institutes of Health (NIH). AC receives funding from the National Collegiate Athletics Association (NCAA) as Director of the NCAA Injury Surveillance Program. BLB acknowledges support from the National Institute of Neurological Disorders and Stroke (NINDS; Award number L30NC113158-02) and National Institute on Aging (NIA; Award number K23AG073528-01) under the NIH. RJE is a paid consultant for the National Hockey League (NHL) and co-chair of the NHL/NHL Players’ Association (PA) Concussion Subcommittee. He is also a paid consultant for Major League Soccer (MLS), the U.S. Soccer Federation, and Princeton University Athletic Medicine and he occasionally provides expert testimony in matters related to mild traumatic brain injury (mTBI) and sports concussion. MM reports a grant from NFL during the conduct of the study as well as grants from NIH, CDC, DoD, and NCAA outside the submitted work. WPM receives royalties from (1) ABC-Clio publishing for the sale of his books, Kids, Sports, and Concussion: A guide for coaches and parents, and Concussions; (2) Springer International for the book Head and Neck Injuries in Young Athlete and (3) Wolters Kluwer for working as an author for UpToDate. His research is funded, in part, by philanthropic support from the National Hockey League Alumni Association through the Corey C. Griffin Pro-Am Tournament and a grant from the National Football League. The other authors have no conflicts of interest to declare.

Additional information

Funding

This work was supported by the National Football League under Grant [GENFD0001903385].No moneys were received for the expressed purpose of writing this paper, and the funding source had no direct involvement or oversight of the preparation of this paper.