Oh no! SB277 is causing autism (except it isn’t)

1 May

When I first started looking online for autism information I was constantly hit with people using public data from California to try to convince me that vaccines cause autism. David Kirby was particularly effective at raising fear. Too bad he didn’t stick around and apologize, as the data now show he was clearly wrong.

Kirby was claiming that the rate of identified autism in California was going up, correlating with more mercury in vaccines. California removed mercury, and autism did not go down. It’s a great lesson. It’s easy to scare people, sell books, get fame. It takes a lot of guts to admit one was spectacularly wrong. Kirby chose the easy road.

That said, we still see armchair epidemiologists trying to make California autism data fit their pet theories. (Yes, SFASA, I’m thinking of you while I write this. But you aren’t the actual topic of today’s post). So I wasn’t surprised to see that people on Facebook were abusing California autism data to scare people about vaccines. You see California passed SB277 a few years ago, eliminating the personal belief exemption for vaccines. In other words, fewer people could opt out of vaccines for their kids. Kids entering preschool (age 3), grade 1 (age 5) and grade 7 (age 11) had to comply with the new law. The kids had to get up to date on vaccines.

Because of this, people are focusing on 3 year olds to see if the data from the California Department of Education indicates a jump in autism People are claiming that the number of 3 year olds in autism category climbed faster than did 4 year olds. And this, of course, means that SB277 caused more kids to get vaccinated and vaccines cause autism. Because everything means vaccines cause autism. (click to enlarge)

(Before one goes too far into this, SB277 doesn’t apply to special education students. So, those 3 year olds didn’t need catch up shots. But, don’t let important facts get in the way of claiming vaccines cause autism.)

When someone makes a claim like that the first thing I think is, how noisy are the data? The second thing I ask myself is, what are they not showing me. In this case, why did they tell us about 3, 4 and 5 year olds and then skip 6 and 7 year olds and show 8 year olds? What happened with those 6 and 7 year olds that they didn’t want me to see? For that matter, what happens with kids older than 8?

So I pulled the data and looked. And I made a table. Because listing these numbers like they did makes it hard to actually compare results. I don’t think they intentionally made it hard for people to compare. I just think they were sloppy. I strongly suspect they were trying to hide something, but not in failing to make a simple table. That all said, here are the number of students in the autism category by age for California in 2015 (pre SB277) and 2017 (post SB277). (click to enlarge)

In the Facebook post we were presented this question:

Other age groups increased 13-15%. What has happened to these poor 3-year olds?

But, we can clearly see that other age groups increased by numbers well outside that 13-15% range. For example, 6 year olds (remember how they just skipped that age group) saw an 18% increase. Not the 24% increase seen for 3 year olds, but a sizable increase. Which might have led a reader to ask, “hey, are these data just noisy?” And, “why didn’t you show me that data point?” Or, “what are you trying to hide?” or “Are you purposely cherry picking to make your point?” Or, “I’ll give you the benefit of doubt and assume you just don’t know what you are doing. Which, given that you believe vaccines cause autism is a very safe bet.”

Let’s keep digging. What does happen with, oh, 16 year olds? OH MY GOD! SB277 caused a huge 22% increase in autism in 16 year olds! That’s almost as big as for 3 year olds! Vaccines are to blame!

Of course, 16 year olds weren’t affected by SB277. They didn’t have to catch up on shots. In other words, there’s scatter in the data. It’s not “Other age groups increased 13-15%” as claimed. It’s “other groups increased between 6-22%.”

Remember how SB277 required older students to get catch-up shots? Like 5 year olds and 11 year olds? 5 year olds were what the Facebook poster used as their baseline, 13% increase. That’s actually below the average increase (which was 16%). How about those 11 year olds? 9% increase. Well below average. So, SB277 caused more autism in 3 year olds, but less in 5 and 11 year olds? Those kids were protected by catch up shots?

No. Let’s say it again–people are trying to put significance on noise. And I think they know it, that’s why they are not showing you all the data. That’s the polite way to say, I think they are trying to mislead you. Maybe they actually believe their claim and, you know, just don’t want you to be confused with all that data that conflicts with their claim. Maybe they believe vaccines cause autism because they have no real skill analyzing data and studies.

There are more important questions here. Questions that actually matter to the autism community.

Go through these data a few times and you should start asking yourself: why does the autism count increase for older kids? 13 year olds in 2015, there were 5874 counted as autistic. 2 years later (as 17 year olds) there were 6084. If autism is obvious, you can’t miss an autistic no way no how, how exactly did 200 or so more of these kids get counted as autistic?

Simple answer–many of these 200 kids were missed before. They were missed. They didn’t get supports and services based on their disability. And this shouldn’t happen. Autism counts, like these, aren’t an accurate count of the real number of autistics in a population. But the fact that autism counts aren’t accurate doesn’t play into the epidemic playbook. This isn’t just a problem for the anti-vaccine community. Yes, they’ve never cared about actually helping autistics. But consider SFASA (San Francisco chapter of the Autism Society of America). That’s a group whose purpose it is to serve autistics. All autistics. No matter whether they have intellectual disability or not. No matter whether they are identified or not. But SFASA denies that autistics have been missed in the past.

Ah, I digress. Back to double checking the anti-vaccine activist claims. So, 3 year olds across the state saw a big jump in the autism count from 2015 to 2017, right? If this is real, then the jump would have to be seen in various locations across the state too, right? For example, in Los Angeles Unified School District (largest in the state), we’d see the same result, right? Simple test. Let’s do it.

LA Unified counted 737 3 year olds as autistic in 2015. They counted 783 as autistic in 2017. That’s a 6% increase. That’s a lot less than the 24% statewide. So if we take the theory that “SB277 caused a jump in autism across the state” then in LA Unified, SB277 is preventing autism!

The anti-vaccine movement has always taken just the data that supports their theory and ignored the rest. They have also always used fear. This is just another small chapter in that story.


By Matt Carey

Acceptance

9 Apr

I accept that people are different.

I accept that different doesn’t greater or less. Just different.

I accept that all people need support in life.

I accept that some people need more support in life than others.

I accept that some people need a lot more support in life than others.

I accept that people who need a lot of support are different. Not less.

I accept that people have inalienable rights.

I accept that a person who needs a lot of support should not be denied their right to life.

I accept that a person who needs a lot of support should not be denied their right to liberty.

I accept that a person who needs a lot of support should not be denied their right to pursue happiness.

I accept that even though these rights are inalienable, they have historically been denied to people with disabilities. And that this is wrong.

I accept that even though these rights are inalienable, they were hard fought. For everyone. And the fight continues, especially for people with disabilities.

I accept that all people deserve respect.

I accept that people with disabilities are often denied basic levels of respect. And this is wrong.

I accept that people with disabilities grow and develop. Accepting disability doesn’t mean accepting stasis.

I accept that happiness is defined by the individual.

I accept that one can be disabled and happy.

I accept that lack of disability doesn’t guarantee happiness.

I accept that my role as a parent is to help my child achieve happiness as best as we can. On my child’s terms.

I accept that my role is not changed due to my child’s disability.

I accept that my responsibility as a parent does not over ride my child’s rights.

I accept that people with disabilities can seek to eliminate their disability. If that is their wish.

I accept that society often fails to accept people with disabilities, and this lack of acceptance can coerce people with disabilities to seek cures.

I accept that nothing is as defining of “self” as much as how one thinks.

I accept that autism at its root involves how a person thinks and perceives the world.

I accept that autism involves both disability and identity to a greater level than many disabilities.

I accept that achieving happiness is more difficult for people with disabilities than for those without.

I accept that my child has a right to privacy.

I accept that protecting my child’s privacy is a greater responsibility due to disability. That I can not use my child’s disability as an excuse to circumvent privacy.

I accept that my role is to identify my child’s advocacy and be the voice that amplifies my child’s advocacy.

I accept that no one achieves everything they advocate for.

I accept that even though it is easy to say “father knows best”, when it comes to their happiness, my child knows best.

I accept that not all parents or autistics accept what I do.

I accept that my own beliefs have evolved over time and will continue to do so.

I accept that I am far from perfect and that I will sometimes fail to keep to all the principles I have accepted.

By Matt Carey

This is a partial list and is subject to additions and revisions.

What Autism Awareness Means

3 Apr

We are often told to be “aware” of autism. But what does that do, really? With awareness comes acceptance. And for my son acceptance means being able to live his life.

A few years ago, I took my son for a walk to our local shopping center. We have done this every weekend day since he was in a stroller. This time we passed Nicco’s hardware store, where they always keep a stock of the American flags my son likes to buy. When they see us pass, they often start a fresh batch of the free popcorn he loves.

At the donut store, Mary and Monica helped him learn to buy things and to wait his turn. We’ve been doing this for years, but they never lose enthusiasm. At the bagel store my son walked right up to the counter as where Sylvia handed him his favorite cinnamon raisin bagel with her traditional “this is for you!” To this day, the workers at the bagel store hand him a bagel with a smile as he walks in. He eats while we wait in line to pay.

At our local market, I got distracted, as parents are wont to do. And my son wandered off, as children are wont to do. I ran to the door panicked because I had to make sure he was safe from traffic. Once I was pretty sure he was still in the store, I ran from aisle to aisle, yelling his name. Still scared. And what I found was a neighbor smiling at me, pointing and saying, “he’s over there”.

She knew us. She was aware that he needed support. When she saw him alone, she kept an eye on him.

He was 7 years old then. He’s 14 now. He still needs a lot of support, and always will.

When my father was growing up, people like my son would be institutionalized. When I was growing up, people with disabilities were hidden. Now that my son is growing up, he lives in a time and a community in which people are aware that he needs support. They accept him and know he deserves respect.

Awareness means my son can be in a community. Acceptance means he can live his life.

With a Perspective, this is Matt Carey.

The above was given as part of the Perspectives program on KQED radio. The original, complete with audio, can be found on the KQED website at What Autism Awareness Means

This is what I presented last year on KQED Radio, and I posted here on LBRB shortly after that. I present it again as we reach another Autism Awareness Day and month.

Kim, the Age of Autism has gotten worse under your leadership

26 Mar

Kim Rossi runs the blog “the Age of Autism”. She’s a parent of three autistic kids. In the past, AoA was managed by someone without any real connection to the autism community: Dan Olmsted. Sadly, Mr. Olmsted passed away (I very much disagree with what Mr. Olmsted did but I never wished him personal ill). So now Kim is in charge.

Many years ago I emailed Kim to propose that we start promoting some stories in parallel. That we find some stories that are important to all in the autism community and start getting some sort of unity in publicizing and advocating on those topics. Ms. Rossi was polite, but it was clear that this wasn’t going to happen. People told me that the primary (by far) focus of Ms. Rossi and the AoA blog was their vaccine stance (they are against vaccines. Yeah, Kim, I know you try to dance around that, but it’s true.). Then they promote bad “medical” approaches to “treating” autism. Yes, Kim, I’m thinking of the example where you sprinkled a novel, synthetic compound mislabeled and sold as a “supplement” on your kids’ food. Then comes attacking actual experts and expertise in areas like medicine, science and the like. Actual advocacy for autistic people is far down on your list.

But I look back on that and I think, you had at least enough advocacy that I thought you were actually interested in it.

No way in Hades I’d make that mistake now. I recently checked in on your blog and I was surprised to see how much worse it’s gotten. I decided to wait until I saw something that actually amounted to advocacy. It was a long wait.

Today you have two articles. One on the suicide of a Sandy Hook parent. It amounts to “Our lives as autism parents are so hard we might commit suicide too.”

The next one is about an autistic adult who was removed from his family in the UK. Actual autism advocacy. You copied the first 5 paragraphs of a news story and gave a link to the story. Your title? First focus “Secret Court”. Well, you tried. A little.

Below is a list of your recent articles. I went back until there was something like autism advocacy.

The world could be a little better for autistic people had you focused your advocacy on actual autism advocacy. Instead you became an anti-vaccine activist. You’ve failed your community. Hard.

Titles of recent AoA articles.

Father of Child Killed at Sandy Hook Commits Suicide in Newtown CT

Secret Court Hearing Takes Son with Autism Away from UK Mother

Women Demand Action from FDA About Breast Implant Danger

What Really Happened In Connecticut? Yale Bailed & Vaccine Knowledge Censorship Continues

Who Are the Anti-Vaxxers?

How Can Brown Injure You? UPS and Merck Want to Bring Vaxes to Your Door

Letter to the Presidents of The Church of Jesus Christ of Latter-day Saints about Vaccination Choice

Common Sense in the Commonwealth of Kentucky’s Governor’s Home: Chicken Pox Once and Done

Student Paper: Vaccinate by Choice, Not by Force

Free Speech YouTubers Noticing Crack Down on Vaccination Topic

The Aspirin a Day Science is Unsettled and on St. Joseph’s Day No Less!

Yale Bailed! Expert Panel Reneges on Vaccine Mandate Debate with Robert Kennedy Jr

An article giving away a book that was donated to your site: “Outsmarting Autism, Updated and Expanded Build Healthy Foundations for Communication, Socialization, and Behavior at All Ages” (almost actually advocacy).

If Teen Consents to Vaccination without Parental Approval Who is Liable in Case of Injury

Robert Kennedy Jr Hosts Press Conference in CT “Should Vaccines Be Mandated?”

Special Education Taking Over in England (nearly on topic. Except your focus is on using the story to support for your failed epidemic idea, rather than actually advocating for better special ed).

Laura Hayes on PRN Radio Monday 3/18

On Vaccines: Our Legislators Don’t Know Vaccines

“Protocol 007”: Merck Scientists Accuse Company of Mumps Vaccine Fraud that May Be Endangering Public Health Today

Lawsuit Claimed Merck Overstated Mumps Vaccine Effectiveness: US Military Preparedness Takes The Hit

You Say Paro-TIE-tis, I Say Paro-Tee-tis Let’s Call the Whole Thing Mumps

#UsToo Open Letter to Washington State Legislators About SB5841 Removal of Vaccine Exemptions

Tesla Uses Merck Whistleblower Punishment Playbook: “Destroy Them Where They Live”

GMOs, Vaccines, Choice, and Informed Consent

Vexed by the Vaxxed: How Measles Is Smarter Than Your Average Bear

Action Alert: CA Senator Schiff Attacking Internet Free Speech

The New Irish Famine: Help for Students with Autism and Their Schools


By Matt Carey

Hey Amazon, here’s another autism-treatment book to consider delisting

15 Mar

As the parent of an autistic child, let me start by saying “Thank You, Amazon, for removing books with harmful fake autism treatments from your offerings.” Seriously. One great example is Kerri Rivera’s book on using bleach to “treat” autism.

For readers who don’t know about this, here’s an article on Disability Scoop: Amazon Yanks Books Touting Autism ‘Cures’.

That said, there are many more books that you should consider removing. One that comes to mind is The Autism Book: What Every Parent Needs to Know About Early Detection, Treatment, Recovery, and Prevention (Sears Parenting Library).

As of right now, still for sale on Amazon.com.

This is by Dr. Bob Sears. As part of the Sears family, he may seem to have some credibility. Or you just missed it.

Dr. Bob promotes chelation, among other dubious ‘treatments’. Here is but one paragraph from his book:

Here’s a page by the Mayo Clinic on autism and chelation. It starts with this line:

Chelation therapy is not an effective autism treatment, and it may be dangerous.

Among the other questionable therapies you can find in his book are antiviral treatments, hyperbaric oxygen therapy and IV immune globulins.

If you are serious about removing books that promote potentially dangerous therapies, consider removing this one.


By Matt Carey

Anti vaccine activists are angry about a new study…and they didn’t even bother to read it

14 Mar

This is a big piece of what the “vaccines-cause-autism” idea is built on. Really bad analyses. Another study shows up showing that vaccines don’t cause autism. People immediately jump to give talking points to their community: “ignore this study! In fact, it’s just another conspiracy to defraud you!!!!!”*

But they know from history, their community doesn’t check. They don’t test whether the talking points hold up. Either that, or they really are this bad at simple math.

One reason I slowed down a lot on writing debunks of the “vaccines cause autism” community is that it’s very repetitive. It only takes a few minutes to see where they make their mistakes. I admit, I have the training and the time to do that checking, but it leaves me wondering. As in, it’s hard to not ask: “are they really this bad at science? Are they so biased they don’t know they are wrong? Or, are they lying?” I don’t know. What matters most is they are wrong. I am grateful that I had the time to spend checking their claims and was able to not get sucked into that world.

That intro aside, there was a recent study that, once again, shows that the MMR vaccine doesn’t increase autism risk. 21 years since Wakefield’s junk study and we are still spending time and money countering his misinformation. When you look at what the autism community needs, it’s just sad to see resources used this way. But I get it. The anti-vaccine community is doing real harm (note the rise in measles in the US and elsewhere). But, dang, I’d like more work done to help my kid.

So, what’s this new study? Measles, Mumps, Rubella Vaccination and Autism: A Nationwide Cohort Study. With the conclusion:

The study strongly supports that MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with clustering of autism cases after vaccination. It adds to previous studies through significant additional statistical power and by addressing hypotheses of susceptible subgroups and clustering of cases.

Thanks for doing this, but, again, the results are not surprising in the least.

Naturally this brought about a big response from the anti-vaccine community. The go-to place for defense of “vaccines cause autism” used to be the Age of Autism blog. I went there and found they just recycled a piece from a guy named James Lyons Wieler. Apparently he was once a scientist, but he now seems to be a guy asking autism parents for money to write bad articles about how vaccines cause autism. In this case has found the “Smoking Gun” for why the MMR study is so wrong.

(1) The smoking gun is the study-wide autism rate of 0.9-1%. The rate of ASD in Denmark is 1.65%. Where are the missing cases of ASD? Given past allegations of this group’s malfeasance and fraud, the rest of the study cannot be accepted based on this disparity alone: the study group is not representative of the population being studied.

Clearly they must be fudging the data!!!!!

This appears to have become the talking point that the anti-vaccine community is passing around. It was picked up by Brian Hooker. He wrote “A Scientist’s Rebuttal to the Danish Cohort Study“:

1. Children were notably missing from the study sample:

First and foremost is the underascertainment of autism cases within their data sample. The study authors used Denmark population registries of children born in Denmark of Danish-born mothers which should reflect the current reported autism incidence in Denmark at 1.65% (Schendel et al. 2018, JAMA). However, the autism incidence within the sample of the Hviid et al. paper is 0.98%, meaning that approximately 4,400 autistic children are missing from this study. The authors do not discuss the discrepancy in the number of cases.

Again, his number 1 point, the missing children!

Even JB Handley (remember him? Yes, he’s back) wrote about this. Focusing his whole piece on this “missing” group in the MMR study: New Danish MMR study shows autism rate of 1 in 100—CDC should rush to Denmark!

2. The most compelling data in the study will never get covered: why is the autism rate in this study only 1 in 100?

Here in the U.S. we’re at 1 in 36! Shouldn’t CDC researchers rush to Denmark to figure out why their autism rate is so much lower than ours? For every 1,000 Danish kids, only 10 have autism. But here in the U.S., we have 28 per 1,000, that’s 177% more autism! I thought Paul Offit wanted everyone to believe the autism rate was the same everywhere? What gives?

Hold on to your seat, Handley. It’s about to get discussed.

I had thought I’d take the easy route and just email the study author for an explanation. That could have answered the big question for Handley, Weiler, and Hooker. But that would take a day or two to get a response from Denmark. Why not just, you know, read the paper? Or, just the introduction?

Under the “Abstract” section of the MMR paper, which has the “missing” autistic kids and a lower prevalence rate:

Participants: 657 461 children born in Denmark from 1999 through 31 December 2010, with follow-up from 1 year of age and through 31 August 2013.

Under the methods section for the earlier Denmark paper, which has the higher prevalence rate:

All live births in Denmark between 1980 and 2012 were identified in the Central Person Register and followed through 2016 for an ASD diagnosis

It’s not that hard to compare the two studies.

One study looked at Danes born from 1999 to 2010. And took data from 2013. This is the MMR study.

The other study looked at Danes born from 1980 and 2012. And took data in 2016.

Apples, meet Oranges.

Seriously, people are surprised that they came to different answers as to the overall prevalence? I mean, this is your “smoking gun”? This is the best the “vaccines cause autism” community can do? If nothing else, one study took data later than the other. You are the “it’s an epidemic!” team, surely you accept that the autism rate is higher in the later dataset.

But, hey, this didn’t take the full 5 minutes I allocated to check the claims of this “smoking gun” against this new study. I still had 4.5 minutes.

So, let’s see if the data really are compatible. Can we take the data from the prevalence study and get the same number as in the MMR study? Yes, I’m a geek and this is what I do. But we just saw that 2 Ph.D.’s (Hooker and Wieler) and a business guy (Handley) didn’t think to do that. Is it really that hard? (I do wonder how Handley made money. Seems like he must have relied on someone else to do the numbers.)

I just wrote about the autism prevalence study: Yes, there are a lot more adult autistics than commonly thought. The real question is what we do with this information. I have the graph from the prevalence study, so I ran the numbers quickly. If we limit ourselves to the autistics in the MMR study (born 1999 to 2010) and take data in 2013, we get a prevalence value of 1.02%.

1.02% using the prevalence study. Compared to 1% in the MMR study.

They are the same. No “malfeasance”. No “fraud”. No “discrepancy”. And, Mr. Handley, no evidence you can use to blame the HepB vaccine for autism.

Now for the dull part. Here’s my math.

Step 1: I digitized the graph. The red points are where I took prevalence data from the graphs. Each line represents 2 birth years, so I took points where for the age of the average kid in each cohort in 2013.

Here’s the summary table from those data points.

I did this fast. Let me know if I made a mistake. That’s why I’m showing my work. It’s not precise because, well, it’s done by hand. Also, there’s the fact that the MMR paper was for kids born from 1999 to 2010. The prevalence study has kids grouped by 2 years. So I have data for 1998-99 where I only really want 1999. It’s good enough. The “age in 2013” is what the digitizer gave me for the datapoint positions I chose. I can’t get exactly, say, 10.5. But, again, it’s good enough.

Anyway, there’s no “smoking gun” as James Lyons Weiler says. There aren’t children “notably missing” as Brian Hooker claims. And the “most compelling data” according to JB Handley is just that he can’t read a scientific paper.

This is a big piece of what the “vaccines-cause-autism” idea is built on. Really bad analyses. Another study shows up showing that vaccines don’t cause autism. People immediately jump to give talking points to their community: “ignore this study! In fact, it’s just another conspiracy to defraud you!!!!!”*

But they know from history, their community doesn’t check. They don’t test whether the talking points hold up. Either that, or they (people like Handley, Hooker and the rest) really are this bad at simple math.


By Matt Carey.

*Yeah, you guys are pushing a conspiracy theory. I know you like to say “oh, he called us conspiracy theorists, therefore we don’t have to listen to him.” Surprise me. Grow a backbone and defend the points in this commentary rather than either (a) ignoring it or (b) dismissing it because I pointed out that you are claiming scientists conspired to fool the world.

Yes, there are a lot more adult autistics than commonly thought. The real question is what we do with this information.

13 Mar

What if I told you that there are a lot more autistics born in the 1980’s than 1 in 10,000. And this isn’t me saying “it’s almost certainly true”. This is fact. I’d hope that one of your first reactions would be, “what should we do with this information to make life better for autistic people?”

Hang around online autism discussions, especially those involving causation, and you will undoubtedly read someone claiming “back in the 1980’s, the autism rate was 1 in 10,000.” People base this on studies done back in the 1980’s and they assume or assert, “nothing has changed since then”. Which is odd, since a whole lot has changes in autism understanding since the 1980’s.

What if I told you that there are a lot more autistics born in the 1980’s than 1 in 10,000. And this isn’t me saying “it’s almost certainly true”. This is fact. I’d hope that one of your first reactions would be, “what should we do with this information to make life better for autistic people?”

If your first reaction was, “this can’t be true. There’s an autism epidemic because of vaccines or some other pet causation theory”, you have your priorities in the wrong place. If you think you are an autism advocate, you aren’t.

Back to the recent study. When I read a recent study from Denmark, I was amazed. No exaggeration, I was amazed to see data so clearly showing that the autism prevalence for autistics born in the 1980’s is much higher than previously reported. I say this with apologies to the study authors, because there’s a lot more in this study. That said, there is also the trend of prevalence* with time. It’s, well, amazing. The study is Cumulative Incidence of Autism Into Adulthood for Birth Cohorts in Denmark, 1980-2012. Basically, the authors mined the Danish Central Person Register for people with autism diagnoses. Here’s the graph from that study (click to enlarge):

There is a phrase for a certain type of graph in my work: spaghetti plots. This isn’t quite that complicated, but it is complicated enough to take some time to walk through. So let’s take that time. Basically, each line shows show data for people born in a given 2 year period as a function of their age. The bottom line, for example, shows data for people born in 1980-81. The data is basically what the autism prevalence would be if someone had reported it in the year for that age.

Let’s take a few examples. Again, for that bottom line (people born in 1980-81). At age 10, the autism prevalence is about 0.02%. So, if you had asked in 1990 (when these autistics were 10), “what’s the autism prevalence for 10 year olds in Denmark”, you’d have been told 0.02%. 2 in 10,000. And if you never looked again, that’s what you’d think the autism prevalence is for people born in 1980. Which is exactly why you hear, “the autism prevalence back in the day was 1 in 10,000.” No one looked again.

But now we have more data. Let’s look at, say, age 20, which would be about year 2000. By this point, the autism prevalence has risen to about 0.13% (about 1 in 800). That’s 6 times larger than when this group was 10. This doesn’t mean that more people “became” autistic. No, it means that people previously undiagnosed were identified. By the time this group was 35 years old (about 2015), the autism prevalence was 0.33% (about one in 300). That’s 16 times larger than when they were 10.

I digitized the data for the 1980-81 group and plotted it. If I get time I’ll make a better graph. It isn’t 100% precise, but here’s that graph (click to enlarge):

Let’s say again what we see here:

1) the autism ‘rate’ for Danes born in 1980-81 is not 1 in 10,000, it’s about 1 in 300. Getting comparable to the autism ‘rates’ reported today.
2) the majority of these autistics were not identified until they were older than 10 years old.
3) the autism ‘rate’ is still climbing today. Yes, they are still diagnosing people well into adulthood.

Now, consider some of the other data in the study. For example, Danes born in 2000-01 had an autism prevalence in 2016 of 2.8%. With no sign of a plateau. When those Danes were 8 years old, their autism prevalence was about 0.77%. Yes, it climbed by a factor of 3+ from age 8 to age 16.

Another way to look at this is: people have been diagnosed throughout the lifespan. And this is still going on.

We’ve only looked at a small subset of the data in this study, but we have to ask ourselves what do we do with these results? I know what I think we need to do:

First, we have to accept that many autistics were not diagnosed when they were children. The autism prevalence in the adult population is much higher than the old data would suggest. It may be (probably is, in my view) close to or the same as the prevalence in children.

Second, we have to accept that the autism prevalence in children is likely higher than what is being reported today. The 2.8% reported for one birth cohort in Denmark is basically the same as that reported in the highest estimates in the U.S.. And there was no sign that this Danish value is the maximum value that will be seen for that cohort, or any other.

Third, and here’s where we need actual action, not just a change in beliefs. If we believe that the supports, services and therapies autistics deserve are different than those targeting other disabilities (which I firmly believe), we should be working harder to diagnose those as yet undiagnosed. This goes for young children as well as adults.

Third, and here’s where we need actual action, not just a change in beliefs. If we believe that the supports, services and therapies autistics deserve are different than those targeting other disabilities (which I firmly believe), we should be working harder to diagnose those as yet undiagnosed. This goes for young children as well as adults.

I am the parent of an autistic teenager. There’s a lot of advice (good and bad) on how to support autistic children. But there’s very little on autism specific supports for adults. And this hasn’t really changed in the past decade or more. One way to get real information is to take a look at what has worked and what has failed for autistic adults. Besides helping those adults and other autistic adults (a good cause in itself), it helps pave the way for the autistic kids coming of age. Well, you know what? It’s hard to do those sorts of studies if we don’t even identify who is and who isn’t autistic in the adult population.

As a final aside, consider the CDC autism prevalence estimates. They use a very different methodology than in this Danish study, which will introduce some differences in the results. That said, the CDC focuses on children 8 years old. The CDC team had good reasons to choose 8 years old, but let’s look at some of the data from this recent Danish study and ask what this tells us about the CDC data. For people born in 2000-2001, the Danish autism prevalence is be about 0.77% at age 8. One might say, “Hey, the CDC autism prevalence for 8 year olds born in year 2000 is 1.13%. Autism is more prevalent in the U.S. than in Denmark.” People making this sort of comparison often then try to fit this into their own favorite causation theory. As in, “Denmark gives fewer vaccines, so vaccines cause autism!”. But, wait. The autism prevalence for Danes born in 2000 is actually 2.8%, well over double the CDC estimate for US kids born in 2000. Makes the comparison of CDC numbers to others a bit of an apples and oranges story.

More to the point, consider graphs of CDC prevalence vs. time. It goes up and up, doesn’t it? Kids born in 2004 have a higher autism prevalence than those born in 2000, right? But if you’ve missed a bunch of the kids because you looked at 8 year olds and many kids aren’t identified by then, can you really say that the number of autistic kids has gone up?

Another way to say this: the CDC data are good for what they are. What they aren’t is an actual census of the fraction of kids who are autistic in any given birth year. Trying to say, “there’s an epidemic” from these data just can’t be done.

But that’s getting off the topic. As I noted above, the real question with these data are not “how do they fit into the failed idea that [exposure x] causes autism”. The real question is, what do we do with the knowledge that there are a lot of autistic adults? That there are a lot of kids, younger and older, who aren’t diagnosed accurately? That autism gets diagnosed through the lifespan? I’ve pointed out what I think above. We act on the data. We do what we should be doing: try to use this information to make life better for all autistics, be they young or old, diagnosed or not.


By Matt Carey

*note–I am not an epidemiologist. Rather than try to keep bouncing between “incidence”, “cumulative incidence” and “prevalence”, I will use the terms more loosely than an epidemiologist would.