Saturday, March 13, 2010

Do football players die younger than the rest of us?


I was wandering around the 'Net this week when I ran into a report that pro football players die significantly younger than the general public, and that each year a pro stays in the game takes several years off his life. You can read such reports here, here and here, some written by doctors and others quoting studies by doctors. The article from Newsmax starts with this paragraph.

It is not a widely disseminated, downloaded or discussed fact that the average life expectancy for all pro football players, including all positions and backgrounds, is 55 years. Several insurance carriers say it is 51 years.

Wow, that's written by doctors and backed up by insurance companies. It must be true. Except that other doctors say it's 59.

I know a little about life expectancy from teaching statistics and this set my spider sense tingling. For one thing, people kept quoting different numbers. For another thing, life expectancy in the 50s is what you get in the absolute worst parts of sub-Saharan Africa, and a large part of those numbers being so low is high rates of infant mortality skewing the numbers down. The data for pro sports athletes won't be influenced at all by infant mortality. You have to live past your first birthday to play pro sports.

I don't have the time to compile massive sets of data, so I designed an experiment to see if these numbers had any validity. I took the 1960 rosters from professional football and professional baseball, selected 100 guys from each sport who where born in 1934 or 1935, then checked on Wikipedia to see if they were dead or alive. If a name didn't come up, I went to the Baseball Almanac or nfl.com. I used Wiki first because its search engine is way better. Also, nfl.com just says "deceased" instead of giving a date of death, and I only had to go there for the most obscure players, a total of three guys.

Since these athletes were between the ages of 24 and 26 half a century ago, we would expect by actuarial probability that some would be dead by now, and of course this is correct. 29 of the 100 NFL veterans born 1934 or 1935 are listed as dead as of March 13, 2010, compared to 30 of 100 MLB players. a completely insignificant difference. The ages at death are slightly different but not that much.

decade NFL MLB
20-29__1__0
30-39__0__1
40-49__1__2
50-59__5__4
60-69__15__10
70-76__8__13

Baseball players who died in this study are more likely to have died after the age of 70, while more football players are somewhat more likely to have died while in their 60s. Even so the average age of death for football players was 63 and baseball players was 64. While these numbers seem low, recall that all the guys on this list will eventually die, and 70% on both lists will be over the age of 74 when they go, so the averages will be over 71 at the absolute minimum, probably several years higher.
If I may critique my own study, it makes sense to do a similar data set for guys born in the mid 1920s and mid 1940s to see if baseball vs. football mortality rates show a greater disparity for those different demographic groups. But this first data set makes the idea that football players have an average life expectancy under 60 to be very far fetched indeed.

To the doctors who put their names on these studies, I'll make you a deal. I won't perform any surgeries or prescribe any drugs, and you should stick to addition, subtraction, multiplication and division, because it turns out math is hard for some of us.

But not me.