Prevalence Is A Red Herring

For years we have been told by our largest ALS organization that disease prevalence is the "gold standard" by which the public sector measures the relative impact of diseases.  That's just the way it is.

Questions from Congresspeople or Senators about constituents with ALS are typically answered with a logical guess based on a number that has been couched and hedged for years -- "As many as 30,000 Americans have the disease at any moment in time."  Carefully worded, eh?

Everybody knows somebodies who lost somebodies to ALS.  Oh, it's so easy to want that prevalence number to be higher so that ALS will rank higher on America's priority list.

That's a red herring -- a big stinky red herring.

We believe that as many people are diagnosed with ALS as MS every year.  That's incidence.  

The number of people living with ALS at any moment (prevalence) is a tiny fraction of those living with MS.  What happened to all the people who were diagnosed with ALS?  Hint:  It's not good.

Does smaller prevalence make ALS a smaller problem than MS?  Heavens, no!  It makes it a much deadlier problem.

High incidence and smaller prevalence form a toxic combination.  If you only look at prevalence, you are missing the boat.  Low prevalence does not make ALS a small problem. It makes ALS a huge problem.

So as the ALS Registry numbers unfold, we'll probably find in the data that there are far fewer than 30,000 people living with diagnosed ALS at any moment in the US.  Should we avoid that low-prevalence fact?  We need to stop leaning on a shaky prevalence guess that feels good for fundraising and speak to the data.  High incidence paired with even smaller prevalence mean that we have a large, urgent problem.

It takes a smart hound not to be thrown off by the scent of a stinky fish.  We need to be smart in the fight against ALS.  Leaning on an assumed "gold standard" with a shaky number isn't going to defeat ALS.

This troubling ramble that worships the red herring is from the report of the CDC's 2012 ALS Registry Annual Meeting at http://wwwn.cdc.gov/als/Download/2012%20ALS%20Annual%20Meeting%20Summary%20Report.pdf

While he did not want to hide information, it could possibly come out that there are not 30,000 people 

with ALS and that it is much lower.  There would be a lot of negative connotation about what this 

all means if there is a map with people in each state.  He could hear appropriators and 

Congressman saying, “You only have 2 people in the whole State of Texas who have this 

disease?”  He thought it was very important that consideration be given to everything in terms of 

research projects, because the intention was never to figure out the number of people who have 

the disease.  If incidence is higher in one state, that is important.  While they should not hide 

information, they should also not be distributing information that could be damaging to the 

research tool they wanted to create, particularly in a budget-conscious environment.  That could 

hurt the overall goal of finding a treatment and cure. 

[Hat tip to The ALS Battlefield for all his work.]