Is a Trusted Agency Leading or Misleading?

The CDC ALS Registry is a product of the Agency for Toxic Substances and Disease Registry (ATSDR), a government agency, generously funded by American taxpayers.

In the ALS Registry Act of 2008, ATSDR was given the primary mission of the ALS Registry --  "better describing the incidence and prevalence of ALS in the United States." That's the mission that should be hanging over every desk and computer of those paid to work on this project.  It should guide every work product.

But it doesn't.

We have a new report publication from the Registry staff -- "Prevalence of ALS in all 50 states in the United States, data from the National ALS Registry, 2011–2018"

https://www.tandfonline.com/doi/full/10.1080/21678421.2024.2358786

Our attention is grabbed by the first line of the report summary --
"This is the first ever paper from the National ALS Registry to report on the state-level prevalence of ALS within all 50 states of the US."

Wow.  And there's a map.  Our eyes are naturally drawn to the map to see how our states rank.  Or to see how states where our loved ones with ALS have lived stack up.

But what they show us in this paper is not prevalence.  It's just not. The CDC can slap a label on a table or a map that calls something "prevalence," but what they are showing us is not what is defined as the total number of individuals in a population who have a disease at a point in time.  What they show us are the people with ALS whom they found.  And they miss a lot of people with ALS.

I live in Indiana, so my eyes went to the map and it seemed to tell me that I'm living in a state relatively low in ALS cases compared with the neighboring states. Yay. That light color seems like a reason to be relieved.  The darker blue Ohio, where Mom grew up and lived long before her ALS, is higher, and Michigan, where she once lived, too, looks like the worst when it comes to cases of ALS.  

But the map is terribly misleading.

You have to read the small print in the report and pay attention.  

The ALS Registry combs government payer files looking for cases of ALS.  It also allows people with ALS to self-enroll in an online portal.  That's how it finds cases of ALS, and it doesn't come close to finding everyone that way. In the 2017 data, a model estimated that it was only finding 44% of cases with these methods.  In 2018 it did better but still missed an estimated 8159 people with ALS nationally, and they have no information about where those missing people live.  Why would you publish a map of where all the people with ALS live without those missing 8159 people?

The numbers labeled as "prevalence" in this new state report only include the cases the registry found.  They simply do not account for the estimated shortfall.  

Any state that does a good job of recruiting self-enrollment in the CDC ALS Registry is going to look dark blue like Michigan.  It's quite likely that my ALSA Indiana Chapter did a poor job of encouraging people to enroll in the CDC Registry. The color of a state has nothing to do with the actual prevalence of ALS in that state.  It only reflects the cases the registry found in payer files and via self-enrollment.  The missing cases are missing, and we have no idea how many cases are missing in each state.

And when you realize this, you see the comments about the northern trend of ALS prevalence to be just silly.  And misleading.

It's not prevalence and calling it "prevalence" is wrong.  And misleading.

This paper simply gives a reflection of found cases, but that's a far cry from all cases.

The paper could be informative as a tool to encourage self-enrollment in the lighter states, but instead, it presents a misleading narrative.

People who are interested in ALS and their environment should not have to scour the small  print to realize what a map is really telling them.

This does not better describe the prevalence of ALS in the United States.  It doesn't provide prevalence, period.

And the next time an ALS organization tells us to ask for a generous appropriation for this project, how about having a candid discussion with them about this misleading report first?