Epidemiological principles in claims of causality: An enquiry into repetitive head impacts (RHI) and chronic traumatic encephalopathy (CTE)

Authors

Lauren V. Fortington, Edith Cowan UniversityFollow
J. David Cassidy
Rudolph J. Castellani
Andrew J. Gardner
Andrew S. McIntosh
Michael Austen
Zachary Yukio Kerr
Kenneth L. Quarrie

Document Type

Journal Article

Publication Title

Sports Medicine

Publisher

Springer

School

School of Medical and Health Sciences

Comments

Fortington, L. V., Cassidy, J. D., Castellani, R. J., Gardner, A. J., McIntosh, A. S., Austen, M., ... & Quarrie, K. L. (2024). Epidemiological principles in claims of causality: An enquiry into repetitive head impacts (RHI) and chronic traumatic encephalopathy (CTE). Sports Medicine. Advance online publication. https://doi.org/10.1007/s40279-024-02102-4

Abstract

Determining whether repetitive head impacts (RHI) cause the development of chronic traumatic encephalopathy (CTE)-neuropathological change (NC) and whether pathological changes cause clinical syndromes are topics of considerable interest to the global sports medicine community. In 2022, an article was published that used the Bradford Hill criteria to evaluate the claim that RHI cause CTE. The publication garnered international media attention and has since been promoted as definitive proof that causality has been established. Our counterpoint presents an appraisal of the published article in terms of the claims made and the scientific literature used in developing those claims. We conclude that the evidence provided does not justify the causal claims. We discuss how causes are conceptualised in modern epidemiology and highlight shortcomings in the current definitions and measurement of exposures (RHI) and outcomes (CTE). We address the Bradford Hill arguments that are used as evidence in the original review and conclude that assertions of causality having been established are premature. Members of the scientific community must be cautious of making causal claims until the proposed exposures and outcomes are well defined and consistently measured, and findings from appropriately designed studies have been published. Evaluating and reflecting on the quality of research is a crucial step in providing accurate evidence-based information to the public. Graphical abstract: (Figure presented.)

DOI

10.1007/s40279-024-02102-4

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