Lou Gehrig's Disease - Motor Neuron Disease - Amyotrophic Lateral Sclerosis
Thought it had been cured by now? Still no known cause. Still no cure. Still quickly fatal. Still outrageous.

Saturday, August 10, 2013

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
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.]


  1. Yes, prevalence is a red herring but so is incidence. Both are low. Nonetheless, great attention and resources have been focused on far rarer diseases (Pompe being one), funding development of targeted therapy. The issue is money to be made in treatment, including revenues for pharma, political currency for legislators, salaries for advocacy/research organizations...for whatever reason(s), ALS hasn't done a good job of smelling like cash.

  2. If we make the case that a singular focus on prevalence is fatally flawed, ALS will surely increase its share of funds such as NIH research funds significantly --

  3. I definitely agree ... we very likely don't have 30,000 people "living" with ALS in the US. If incidence is approximately 5,000 per year, the death rate is 15-18 per day and 80% of us only live on average from 2-4 years - how could we possibly be anywhere near 30,000 "living"? Especially when we have NO life extending treatments available.

  4. You could look at NIH funding / per yearly deaths.

    ALS: 5000, $44M

    Hepatitis: 7,564, $378M in NIH spending (5.7x more funding per death than ALS)
    HIV:8,369, $3.1B (42.1x)
    Cervical Cancer: 3,939 $113M (3.3x)
    Asthma: 3,404 $230M (7.7x)

    Drug Abuse: 40,000 $1B (2.8x)
    Firearm homicide: 11,078