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In 1987, National Football League players went on strike. As a response, NFL teams scrambled to fill their rosters with “replacement players,” individuals who had some experience with college or professional football, but who weren’t part of NFL rosters that year. Replacement games – which lasted three weeks – were deeply unpopular with fans. The replacement players themselves became a footnote in sports history.
It turns out these players may actually play a critical role in football today – by helping us understand how playing in the NFL affects long-term health.
There is considerable interest in understanding how professional football affects health. The main concern is that injuries to the brain may shorten the life of NFL players. Lifestyle choices, such as substance use (either during or after a player’s career), and listlessness and loss of purpose after early retirement are other factors that may also raise the risk of early death.
But finding an answer is difficult. The key issue is that NFL players represent some of the best, most uniquely trained professional athletes in the world, which means that any comparison of health outcomes needs to be based on a similarly athletic group of individuals who, for some reason, did not play professionally.
Previous studies have compared NFL players to men of similar age and race drawn from the general population – regular people like us. These studies find that NFL players have a much lower risk of death. While comparing NFL players to the general population might look good on the surface, the two groups are actually nothing alike. To make an NFL roster, players have to be in incredible shape. NFL players also make more money than most and have access to the very best health care while they are playing, which can improve health, too.
This is where the replacement players come in. Unlike members of the general population, replacement players often had prior experience playing football and maybe even similar training, but their professional experience was typically limited to just the strike games. Replacement players are much more like NFL players than the rest of us – but without the prolonged exposure to the game. This makes them an ideal comparison group for NFL players.
In our recent study, published in JAMA, we compared the life expectancies of professional NFL players who debuted between 1982 and 1992 to the life expectancies of replacement players from the 1987 strike.
We found that the risk of death in any given year after retirement was 38 percent higher among NFL players. These results are only suggestive, however, because the overall death rate was low. By the end of our study (December 2016), the players were on average only 52 years old and only a small proportion (4.2 percent of replacement players and 4.9 percent of NFL players) had died. These low rates of death make our estimates imprecise. Even though we can’t be truly certain that the risk of death was higher among NFL players, our estimates do allow us to rule out the possibility that NFL players have substantively lower risk of death than replacement players – which is what studies comparing NFL players to men in the general population have found.
We also looked at causes of death. Both NFL and replacement players were most likely to die from heart disease. But there was a greater proportion of deaths from traffic accidents, unintentional harm (typically accidental overdoses from prescriptions drugs or drugs of abuse), and neurological diseases – like ALS – among NFL players. The higher risk of death from neurological disease among NFL players has been found in other research, as well.
Comparing measures of career NFL player and replacement player health over time will help increase statistical precision. Moreover, studies that go beyond just looking at life expectancy, by comparing measures of physical and mental health among NFL players to those of replacement players, can provide a more detailed understanding of how player health evolves over time.
With more research, these replacement players – far from being forgotten – might be able to play an even greater role in history by helping us to better understand how playing in the NFL affects long-term health, and identify ways to improve football player health in the future. That would be a win for every team.
A version of this post appeared in STAT First Opinion.