There are only estimates. Nobody really knows for sure. Even agencies that are supposed to be experts don't agree on the extrapolations. Without a registry, we'll never know what the right number is.
From The ALS Association www.alsa.org "Based on U.S. population studies, a little over 5,600 people in the U.S. are diagnosed with ALS each year. (That's 15 new cases a day.) It is estimated that as many as 30,000 Americans have the disease at any given time."
From The National Institute of Neurological Disorders and Stroke www.ninds.nih.gov "As many as 20,000 Americans have ALS, and an estimated 5,000 people in the United States are diagnosed with the disease each year. ALS is one of the most common neuromuscular diseases worldwide..."
From the MDA-ALS Division www.mda-als.org Before 2008 they didn't seem to venture a guess as to the patient population. The ALSTDI forum has reports of people seeing the MDA use an American population of 40,000 in a presentation; however, the MDA 2008 press guide for ALS Awareness Month cites 30,000-35,000.
From the ALS Society of Canada www.als.ca "Approximately 2,500-3,000 Canadians currently live with ALS."
From the International Alliance of ALS/MND Associations on the internet www.alsmndalliance.org "Once thought rare, it is in fact quite common. There are nearly 120,000 cases diagnosed worldwide each year. That is 328 new cases every day!"
From The Robert Packard Center for ALS Research at Johns Hopkins www.alscenter.org "It affects as many as 30,000 in the United States, with 5,000 new cases diagnosed each year... The incidence of ALS is five times higher than Huntington's disease and about equal to multiple sclerosis. "
All of the above are estimates. They are based on prevalence rates found in small studies. The prevalence is multiplied by the total population to extrapolate these estimates. The estimates you see above have been published by these organizations for years. One would think that the estimates should grow as the United States and world population grow every year.
It gets really bad when agencies start using each other's numbers!
From a recent marketing piece from the ALS Association-- "For the 350,000 people worldwide currently living with ALS, ..."
A subsequent question to ALSA from ALSCounts -- "...the 350,000 number made me scratch my head. Do you know how they based that estimate? If I go backwards... since the U.S. has about 4.6 pct of the world population, the 350,000 * .046 = 16,100 U.S. PALS. Way low? ... If I go frontwards from 30,000 U.S. PALS... 30,000 / .046 = approximately 650,000 worldwide PALS. If we would get a registry, you wouldnt have to mess with these messages from me! ...Thanks if you can find any insights into that 350,000. If I did an arithmetic goof, Ill be happy to have it pointed out."
The reply from the ALS Association -- "This is provided through the MND Alliance (Motor Neuron Disease)."
Prevalence and Incidence
From Agency for Toxic Substances and Disease Registry www.atsdr.cdc.gov "Sporadic ALS accounts for over 90 percent of all ALS cases. Reports from the United States and other countries indicate an annual incidence rate of 0.2 to 2.4 per 100,000 population and a prevalence of 0.8 to 7.3 per 100,000 population "
"...a prevalence of 0.8 to 7.3 per 100,000 population..." That's quite a swing. When you apply these numbers to populations, they just don't make sense. They would lead you to think that there are from 2,700 to 25,000 Americans with ALS at this moment. Imagine getting an estimate from a contractor, "It could be $2,700 or it could be $25,000 but it's likely to turn out way more than $25,000." We wouldn't tolerate that when our money is at stake. Why do we tolerate the lack of accurate patient data when lives are at stake?
.................................................................................. How can we connect the dots if we're not even collecting the dots? ..................................................................................