Plot of the Week 5

Last week, David Epstein (from Sports Illustrated) reported that, contrary to popular belief, recent studies have shown that NFL players actually have a longer life expectancy than non-NFL players.  You can find his original article here.  The printed SI article included some graphics, but I thought that the data could be visualized better.  So I am presenting the same data as in the article but in a more effective way.

The first plot shows that fewer NFL players have died than would be expected in the general US male population (*when looking at men with similar age and race to the NFL players in the study), 334 vs. 625, a 43% decrease.  The different colors represent different death causes.

The second plot looks at the expected and actual death rates for 3 special death categories: suicide, heart disease and cancer.  In each of these categories, NFL players have a lower death rate than the US male population (including suicide, 9 vs 22, a 59% decrease!!!).

The original academic paper that reported these numbers and results can be found here.  I only glanced through the paper for a minute, but the statistical methods seemed reasonably sound to me.  Even though this data was collected in 2007, these number seem to suggest that anecdotal evidence (i.e., the media) is responsible for exaggerating the link between playing in the NFL and suicide.

The Mystery Behind NFL Suicides

If you haven't heard, former NFL player Junior Seau was found dead in a possible suicide.  This event has the media up in arms again about the link between concussion, depression and suicide in football players.  I'm sure that its only a matter of time before Congress steps in to voice their opinion*.

While pro athletes live glamorous lives while playing, many retired athletes struggle with depression after falling out of the limelight and other personal struggles (bankruptcy, family issues, not knowing what to do when retiring at age 30, etc), regardless of sport.  I wanted to look at the data for suicide numbers between the NFL (a high contact sport) and other non-contact professional sports, hoping to find a higher rate among NFL players than other athletes.

However, for all of the press that the NFL and suicide are getting right now, I challenge you to find the number of former NFL players who have committed suicide - I can't find it!  Here's what I did find:

• Cricket is known to have the highest suicide rate in professional sports, with over 150 known cases in the 20th century.  See the link here for a good explanation of possible reasons for this.
• As of 2005, there have been 76 suicides of former MLB players.
• All we have for NFL suicide numbers are anecdotal stories, which play towards the heart but not the mind of statisticians.  

I realize that researchers have shown a link between brain injuries sustained playing in the NFL and depression, which has at times has led to suicide.  But without the data, we can't conclude that former NFL players are any more likely to commit suicide than other athletes, such as MLB players or cricketers.  Extra credit to anyone who can help me find this data.


*Showing how effective their MLB steroid hearings were, Rogers Clemens is currently in court for possibly lying about possibly taking steroids and Ryan Braun, who last year failed a drug test and got off on a technicality, is on the field making millions playing in the MLB.