Abstract
BACKGROUND: Multiple risks predispose professional football players to adverse health outcomes and, in extreme cases, early death; however, our understanding of etiological risk factors related to early mortality is limited. PURPOSE: To identify etiological risk factors associated with all-cause and cause-specific mortality among National Football League (NFL) players. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: Articles examining all-cause and cause-specific mortality risk factors among previous NFL players were identified by systematically searching: PubMed, PsycINFO, Web of Science, and Google Scholar from 1990 to 2017. Study eligibility and quality were evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. RESULTS: A total of 801 nonduplicated studies were identified through our search strategy. Of these, 9 studies examining 11 different risk factors were included in the systematic review. Overall, the risk of all-cause and cause-specific mortality was lower among NFL players than among the general male population in the United States. Nonwhite athletes, those in power positions, and those with a high playing-time body mass index (≥30 kg/m(2)) were associated with elevated all-cause and cardiovascular mortality risks. CONCLUSION: Methodological issues associated with the examined all-cause and cause-specific mortality risk factors preclude a definitive conclusion of etiological protective or risk effects. Comparison groups less prone to selection bias ("healthy worker effect") and a life-course approach to the evaluation of suspected risk factors are warranted to identify etiological factors associated with early mortality among NFL players.