Map of life expectancy at birth from Global Education Project.

Wednesday, June 08, 2005


I'm not talking about that sissie english game where they run around the field kicking a ball back and forth for an eternity and nothing ever happens.

I'm talkin' 'bout real foobaw. Murrcan foobaw. Where men are men and ligaments are nervous.

Now, everybody knows that you can get hurt playing football. But the question, "How dangerous is football" is a perfect illustration of the limitations of scientific discourse in addressing questions with social or moral meaning. An epidemiologist needs a definition of an "injury," a rate base -- a denominator -- and a source of data. Based on combinations of these choices, one can generate almost any number one wishes.

The following information is from Mueller, Zemper and Peters, "American Football" in Caine, Caine and Lindner (eds.) Epidemiology of Sports Inuries. Human Kinetics, Champaign, IL. (1996)

The most popular definition of a football injury is a lesion that causes the player to miss at least one day of practice. The most popular denominator is called the Athlete Exposure (AE), which means a player attending a game or a practice. Based on these definitions, injury rates in both high school and college, at least up till around 1992, were about6-8 per 1,000 AE. Should this concern us?

Not on its face. After all, these guys presumably want to play football. If the only consequence of an injury is that they miss a day, that's presumably better than not playing football at all and their priority will just be to get back in the game. If a high school player has to spend a week on crutches, he'll probably get more attention from the girls and he might not have to take the trash out that week. That's not such a bad deal. There might be some medical expense for an X-ray or an orthopedist's opinion, but what the hell, football is already expensive -- equipment, coaching, real estate -- so evidently people don't mind paying for it.

So we need a definition of an injury that we really care about. Mueller et al refer to "catastrophic injuries" -- "injuries that result in death or some type of permanent disability." Nearly all deaths from football injuries result from head or neck trauma. The number of such fatalities fell dramatically after 1976 when the rules were changed to prohibit using the head as a ram -- "spearing" -- in blocking and tackling. With the exception of 1986, when there were 11 such deaths, the numbers per year were in single digits from 1977 through 1992 and indeed, in 1989-1992 inclusive there were a total of only nine -- all at the high school level. This is out of more than 1.5 million high school football players, so the risk is lower than the risk of riding in a car. I can tell you that in elite college and professional football, this rule is very strictly enforced.

So-called "indirect fatalities" -- from heat exhaustion or cardiac arrest -- have been more persistent. There were 8 in 1992. Some of these individuals undoubtedly had heart abnormalities and might have died during any form of exertion. Others may have been severely dehydrated. There used to be a widespread belief that athletes should not drink water during practice. This myth has been debunked, and hopefully the number of such incidents is now reduced.

Spinal cord and brain injuries resulting in "incomplete recovery" are slightly more prevalent. Mueller et al do not fully describe the source of their data, so I have no idea how complete or accurate it is, whether it depends on medical evaluation and reporting, or precisely how the concept is operationalized. But evidently beginning in 1977 there has been a reporting system for such injuries. The annual rate per 100,000 high school players (which is probably of more interest to parents than the rate per AE) has ranged from 0.07 to 1.0. The rate for college players, of whom there are only 75,000, has been far more volatile, ranging from 0 (in many years) to a high of 2.67 (i.e., a total of 3 -- also in many years). Continuing improvements in equipment and training methods have no doubt further reduced this number. We don't have much information about the severity of these injuries, which presumably range from total quadriplegia to fairly minor limitations in motor control, but any permanent spinal cord or brain injury is a significant misfortune.

Nearly 100% of professional football players wind up with osteoarthritis, or other permanent damage from wear and tear.

Okay then. Does that mean advocates for public health should campaign to ban football? Hell no. In the first place, you'd have to weigh these costs against the indisputable direct health benefits of vigorous physical activity. Football training includes strenuous aerobic conditioning and also weight bearing exercise which builds bone strength. Advocates for the game think it "builds character" or something like that. I have no idea what the net effect is of playing football on longevity or long-term quality of life, but these numbers alone don't prove that it's negative. (And of course, you have to operationalize those concepts as well, which is a profound difficulty.) You could certainly argue that safer forms of exercise are available, but then you would have to ask how many of the players would engage in them if not for the specific allure of football. Just as important, there is risk in most life activities, which we readily accept -- driving, crossing the street, eating sushi, taking a shower, mowing the lawn, climbing Mt. Everest. The only question is whether it's worth it.

So the argument about the value of football really comes down to its role in the culture and its aesthetic properties. Personally, I happen to like it. I was a Patriots fan when they were a laughing stock, and later during the troubled years when Troy Brown personally constituted their only redeeming social importance. Now I'm in hog heaven. I appreciate the complexity of the game, its extraordinary demands, the courage and skill of the players. American football is, as far as I know, unique in its demand for teamwork. On nearly every play, if just 1 out of 11 players doesn't execute his assignment, the play will fail.

On the down side, football players, like other athletes in popular sports, are often flattered and indulged as youths, and may become arrogant and socially offensive. But that isn't the fault of the game. Football players are often stereotyped as dolts, but in fact, to play the game at a high level requires considerable intelligence and discipline. It seems to many people a distortion of social values that elite professional athletes are so highly paid when social workers and school teachers are impecunious. This is a result of limited supply, of course. Professional sports selects out people with very rare capabilities, who are in a position to demand high pay. We don't have to watch. Part of the aesthetic of football is violent collision and physical intimidation, which people tend to associate with testosterone poisoning. But more and more women are playing football. There are now 3 women's professional leagues in the northeast U.S. One of my coworkers is a professional offensive linewoman. (I know what you're thinking -- she is not a lesbian.)

The point of all this? The science of public health can supply us with facts, but which facts and what numbers it gives us depends on the questions we ask, the categories and definitions that we use, and the reliability (i.e., accuracy) and validity (i.e., applicability to what we really care about) of the data. After that, what we do with the facts, what they mean to us, whether we care about them, what choices they lead to, depend on our values. And the effective functioning of democracy requires the democratization of science. I've deliberately chosen a somewhat frivolous example to introduce this problem.

What else might young people and their parents want scientists to tell them in order to make personal decisions about participating in football? To make decisions about the football program in their own public schools, and state college systems? Who should be responsible for the medical bills and long-term care needs of seriously injured football players? How well can people understand the information that already exists, and how accessible is it? How does the kind of quantitative information presented here, based on strict operational definitions of entities, inform these decisions, if at all? All of these problems are equally vexed in environmental regulation, alcohol and other drug abuse policy, food and nutrition policy, you name it. How can we do science for the people?

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