Using previously collected data from a 1990 National Football League pension fund database, the Lahman Baseball Database, and the National Death Index, Nguyen et al1 examined former National Football League and Major League Baseball players who had played at least 5 seasons between 1959 and 1988 and had died between 1979 and 2013 in the United States. Using Cox proportional hazards regression models, the authors1 observed that rates of all-cause, cardiovascular disease, and neurodegenerative disease mortality were higher among former American-style football players than among former professional baseball players.
The ongoing research on this unique population is important because these findings can help drive the discussion on how best to support athlete retirement transitions. We commend Nguyen et al1 for their study, their careful consideration of the 2 data sources, and particularly their efforts to ensure comparability between 2 distinct data sets. As noted by the authors,1 previous research has compared various control groups ranging from the general US population2,3 to replacement players during a strike4 to cohorts of former professional football players. Yet, each control group is uniquely limited in comparability to the exposure group of interest, former American-style football players. Nguyen et al1 carefully note that they “did not have information on other factors that may contribute to neurological and other conditions, such as genetics, family history, or lifestyle and environmental risk factors.”1 As a result, despite the growing body of literature, there are still gaps in the literature that need to be addressed. We strongly echo the call by Nguyen et al1 for “the need for cohort studies of football players with more detailed information on specific aspects of players’ football experience to isolate what specific factors are associated with increased cardiovascular and neurodegenerative risk.”1 Future research must aim to also consider additional risk factors extraneous to participation in professional American-style football.
Furthermore, this body of literature joins previous research that has found repetitive head trauma to be associated with adverse long-term outcomes.5,6 Yet, the research community has practiced caution in describing such relationships as “associations” and refrained from making causal inferences. We urge that readers proceed with the same caution because this line of research is still in its infancy, and studies with stronger designs, built on the platform laid by this and other studies, are needed before making causal inferences.
It is also important for readers to note that these findings are from professional athletes who played predominantly within the 1960s to 1980s. Of course, American-style football is a sport that allows for intentional contact, and there may be an inherent risk of injury involved for athletes of any era. Yet, American-style football has arguably evolved into a safer sport now in part owing to rules such as banning “spearing.” In contextualizing the findings from the study by Nguyen et al,1 it is essential to consider the heterogeneity in athlete profiles between that era and the modern era. As such, we urge readers to consider the generalizability of these findings to current professional American-style football players and, moreover, to the many active amateur American-style football players at the collegiate, high school, and youth levels. With that said, we note that a longitudinal prospective cohort study that follows up youth American-style football players through adulthood and to death may be unfeasible.
Finally, although we applaud the many efforts to provide safer sports environments for current athletes, it is equally as important to advocate for tertiary prevention for former athlete populations. In other words, strategies to help these populations better manage the issues they face after retirement, as well as the posited long-term adverse outcomes, are desperately needed. Moreover, we believe that care for former athletes is a responsibility that belongs to all sports organizations and not just those associated with football. All former athletes deserve the opportunity to receive care at any stage in their postretirement phase.
Studies such as that by Nguyen et al1 are important in continuing dialogue centered on athlete health and well-being among researchers, former athletes and their families, the media, and the general public.7 We look forward to the future research efforts of this and other research groups as we aim to disentangle the paradigm of risk factors associated with adverse health outcomes and, more importantly, to conceptualize strategies for providing care to populations of former athletes. The continued interest in this topic will inevitably help produce strategies that can augment the health-related quality of former and current athletes alike.
Published: May 24, 2019. doi:10.1001/jamanetworkopen.2019.4222
Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2019 Kerr ZY et al. JAMA Network Open.
Corresponding Author: Zachary Y. Kerr, PhD, MPH, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, 313 Woollen Gym, Campus Box 8700, Chapel Hill, NC 27599 (firstname.lastname@example.org).
Conflict of Interest Disclosures: None reported.
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Kerr ZY, Chandran A, DeFreese JD. Considerations for Present and Future Research on Former Athlete Health and Well-being. JAMA Netw Open. 2019;2(5):e194222. doi:10.1001/jamanetworkopen.2019.4222
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