Monday, October 22, 2007

The myth of the autism epidemic

I recently started AutismNewsBeat.com to provide working journalists with an evidence-based resource for writing about autism. Having spent several years in a newsroom, I understand how the pressures of deadlines, combined with an unfamiliar topic, can sometimes lead to inaccurate coverage. By offering constructive reviews of press coverage, and links to accurate and informative articles and studies, I hope to change the way some in the press approach this complicated and emotional topic. I am also the father of a 12-year-old boy with autism, and my interest in this topic is just one more of the many gifts my son has given me.

Popular press coverage of autism is bedeviled by a number of misperceptions. Chief among these is the idea, stated with much certainty, that we are in the midst of an autism epidemic. In fact, it is far from certain that the prevalence autism spectrum disorders is any greater today than in the past.

But the myth of the autism epidemic will not die. It's like Jason in the
Friday the 13th movies - you can shoot, burn, drown, crush, stab or gut the monster, but it will always return for the sequel. Neither facts or logic will deter the myth's defenders, because the political and business agendas of so many rest on its very existence. Without an epidemic, claims that vaccines cause autism are moot, and the overnight quack-cure industry goes into Chapter 11. These things are certain to me, and will become clear to others as more reporters rely on evidence rather than the agenda-driven fear mongering of others.

Epidemic promoters point to an increase in autism diagnoses over the last 20 years, from 1:2,100 to 1:166. There are several reasons for this change that have nothing to do with an epidemic. For example, th
ere were no standard criteria for autism in the Diagnostic and Statistical Manual (DSM) until 1980, and the criteria in the DSM have undergone several changes since then. It's entirely possible that Jeremy, the autistic college student whose story is told here, wouldn't have been labeled autistic 20 years ago.

Imagine if the definition of "legally blind" underwent the same diagnostic change as autism. Today, approximately 1:250 persons in the US is legally blind, defined as having 20/200 vision or worse in the better eye that cannot be improved with corrective lenses. If the definition was changed to 20/100 vision, thousands more would qualify for the tax breaks and services, leading to greater awareness and more diagnoses. The phrase "blind as a bat" would be replaced by "blind as a sheepdog", and a faux epidemic would be born, albeit with less outrage.

So why the outrage over autism? There are a number of factors which make autism a fertile field for fraud and misunderstanding, but the key enabler is the very thing most capable of driving a stake through the monster's heart: the internet. Joseph at Natural Variation explored the internet's pernicious influence on autism here.

Enter "autism epidemic" into a Google search and you'll receive 107,000 hits. Of the first ten hits, six lead us to quack medical sites, misleading blog entries, and poorly-sourced news stories. One is a dry but accurate Wikipedia entry which explains the crucial difference between incidence and prevalence. As we delve further, we come to a 2005 Medscape interview with two well-respected researchers who explain the epidemic that wasn't. Another hit leads us to a Time Magazine interview with Dr. Roy Grinker, author of Unstrange Minds, a must-read book for anyone who wants to understand the science and politics of autism. The last hit is a favorable review of Grinker's book by blogger Kristina Chew, PhD, of AutismVox.

The problem with so much information available to so many is that although the question of whether an epidemic exists is scientific, a critical mass of misinformed on-line commentary rests on how "real" the epidemic feels. Typical is this comment left on AutismVox:
What remains to be true is that I personally know at least 50 autistic children. I don’t need someone to tell me they’re autistic. Their behaviors scream it to me. 10 years ago I knew one child who exhibited the behaviors we now know as autism. And most people reading this know the same exact thing.
And the anecdotes lodge themselves in the national conversation over autism that play out in the popular media every day.

So I thank Ashley and KOMU for this experiment in participatory journalism. May it lead to higher standards for separating the wheat of truth from the chaff of nonsense. In future posts I'll write about some other enduring myths that bedevil or understanding of autism.

28 comments:

Unknown said...

Are you for real?

The only thing that comes to mind is you decided to come here looking to make a name for yourself in some twisted way.

Why in the world would you write such mindless drivel?

Is it that you are just uneducated, or is it that you are so bitter about your son being autistic, and having to raise him during a time of limited awareness, that you're looking to stifle any attempts to bring attention to a cause that which you have obviously come to believe is benign?

Next you'll be saying "we've always had high instances of breast cancer, but we used to think it was just hardened mothers milk".

Going from 1 in 10,000 to 1 in 150 is guess what, an epidemic. That's a hard statistic. The fact that people are now seeing autistic children EVERYWHERE is not simply the anecdotal evidence which you have belittled it to be, it's a result of the 1 in 150.

May I ask, WHAT kind of person sees fit to take the time to deliver blows to a cause like this? Do you hang out at the local supermarket and trip old ladies as well? Turnover wheelchairs for sport?

Get some therapy, really.

Anonymous said...

Why is it that parents of children with autism get so militant when someone gets to the point that there definately IS an increase in number of diagnoses connected to the widened umbrella of autism spectrum disorders that are considered now, more than ten years ago. It is a fact that many kids are being diagnosed and receiving services for ASD than would ever been diagnosed previously. That is actually good news, kids are getting the correct diagnosis, help in school, and private therapies in order to address many issues earlier. The fact that it is not seen by some as an "epidemic" doesn't mean that they aren't concerned, and understand that there are many children diagnosed. Try to read with an open mind, and see the issue from someone elses point of view. The author is not threatening or belittling the fact that many children have autism. As the mother of two on the spectrum, and a pediatric therapist, I am happy that the spotlight now shines on autism, leading to increased awareness and early intervention services. Why attack an opinion, just because it is different than your own?

Anonymous said...

I must say being a mother of two autistic children I can tell you that this is an epidemic and I for the last 8 years have embraced this to be a fact and a part of my everyday life and it being somethig taht will never go away. In every epidemic there are going to be quacks and articles tat don't ring true or paint a truethful picture of Autism . But I hate to disappoint you there pal if you are a parent of an autistic child it is about time you embrase the fact that he has it and there are peopel inthe world that are genuinely trying to raise money for a cure to reduce the high amounts of families struggling with this disorder. Cause guess what right now in these early stages of this if the familes struggling with this don't have each other for support and to learn from each other's experiences than we have nothing . get a clue there pal and jump on the wagon and get a better understanding and get a little bit more educated and then come back and post anoter blog .
Thanks

Anonymous said...

I have TWO boys with Autism, Just because they now know how to see most of the forms of autism, and they were unable to years ago does not make it any less real. Or make those who now are known to be autistic and would not have been known as 20 years ago any less in need of help.

I can't believe a parent of an autistic child could be so heartless.

Anonymous said...

I am standing up and applauding AutisticLiving's reply. Your blog is a terrible example of "Combating Autism." In fact, it promotes just the opposite. You will likely receive a string of negative replies to your blog. The only combating I see is against the very community in which you are a part of because of your son. That's a crime.

dsmiley said...

Unless you live and breath the Autistic life then you should not be writing about it! because you have no clue about the impact this has on peoples lives and how many children it has effected in this world.MYTH Is NOT a word to be used when dealing with Autism Spectrum Disorder . I Say epidemic is the Key word in this Disorder .Now instead of trying to get fame from writing articles on something apparently you have never researched I say put your pen where it needs to be in helping find a cure that robs our children of so much.
Grammiesmiley momwith

AutismNewsBeat said...

The purpose of Ashley's blog, as I understand it, is to create a place where individuals can share the evidence that informs their views. I presented my evidence. I look forward to reading yours. Ad hominem attack and post hoc reasoning cheapens KOMU's efforts to raise the level of the debate. The station, and our children, deserve better. Thank you for your comments.

Anonymous said...

All I can say is poor guy. I'm the mother of son with autism. I'm not a doctor or scientist, so I won't pretend to be one. Seriously though, who really knows? How do we know that autism wasn't just as prevalent 10 or 20 years ago? I think this is another perspective to consider. Maybe it's not right, but you can't go shutting down another parents perspective on things. It's simply the way he thinks about it. I'm sure no two people who have been touched by autism will view every aspect exactly the same.

Anonymous said...

I get the distinct impression you're one of those fathers who really has very little to do with the day to day care of his autistic child. I'd like to hear whether your wife feels the same way you do about the Autism Epidemic.

Anonymous said...

As the mother of an 18yr old with autism I can state that autism has been around for awhile. I have had to deal with the frustration of having treatments for the disorder that are only effective if you use them by age (5 years younger than my son's current age) I can not believe that the current increase in Autism is due entirely to better dianoses. I am thankful that there is better dianoses though because more people will get better treatment. We must not forgit that whatever the reason or whatever we call it that we have a very large population of autistic children growing up and in need of help. More programs are needed to be developed so that they can live happy productive lives. In fighting and name calling does not help those who need our help...the autistic people themselves.

Anonymous said...

I get the distinct impression that your distinct impressions are not reliable. That's the problem with anecdotal evidence, too. You simply don't have enough data to form an accurate description, so you fill in the blanks with "distinct impressions" which may or may be based on anything more than your personal bias.

Anonymous said...

I get the distinct impression you're one of those fathers who really has very little to do with the day to day care of his autistic child. I'd like to hear whether your wife feels the same way you do about the Autism Epidemic.

Anonymous said...

Whether there's an autism epidemic is a scientific matter. It's not something to be resolved by means of ad-hominems or through personal experience. It just so happens that the data shows a likelihood of diagnostic substitution from mental retardation and learning disability, plus an increasing trend in the diagnosis of children who are not cognitively disabled, in addition to increased labeling of older children and adults.

Tonya said...

I am trying to comment on the said article. If there is not epidemic, why do I have identical twin boys, both on the spectrum? Their vaccine schedules were different, slightly, and by all odds I should have had only one child on the spectrum. This article makes me angry. Doing away with termisol and aluminum in our vaccines would be a great beginning!!!! After that, the article would ring true.

Anonymous said...

Call it whatever you want, the fact remains that there are a ton of kids out there that need support. Epidemic, change in rationale, change in guidelines, the fact remains that there are a lot of children that need therapies. I know I am the mother of twin boys, BOTH have a spectrum diagnosis; and I teach in a preschool. It is difficult and expensive to get them the therapy that they require. I do not care what the reason for the increase in awareness, I am just glad that I can get my kids the help that they need. I think that if more parents become aware of the problem, they will get their children the help that they need. As a parent, getting my children the means to grow to be a productive citizen is my top priority. So I do not care if they call it a three legged dog, it is what it is. There is a lot of kids that need help and not enough services to help them. Attention and money is what is needed, not a fight over whether it is an epidemic or not.

Ryans Dad said...

I am the proud, happy, frustrated, tired, exhausted and powerfully active father of an awesome 9 year old son with Autism.

Somebody has put the blinders on you or you are just seriously ignorant to the obvious.

Our son was on a perfectly normal path until his 2 year vaccination. Two days after it, he stopped talking all together, stopped looking at my wife and I in our eyes and became a completely different person. I have talked to hundreds of parents with the same story or worse, like their kids developing seizures!

Here's a little test for you. The vaccination schedule went from 10 vaccinations to 33 vaccinations in the late 80's and it is now currently over 70 vaccinations. Here's a good questions for you and anyone that is curious. What epidemic occurred that constituted this huge increase in vaccinations?

Here's another question! Have you ever researched what the effects of mercury poisening are? Interesting enough, I have. Most of all of it is the exact same symptoms of the symptoms of Autism.

Here's one more question for you and it's a good one. Why did our current president sign into the terrorist act that no drug company could be sued for any complication that might or could happen from a child or person being vaccinated from that drug company’s product?

I find it ironic that he's protecting big Pharma in the Terrorist act. Is he trying to give us a hidden message here?

Am I paranoid? No way. These are just the facts and they can not be reputed because they are true and documented.

Here's one more interesting tidbit. China did not have any cases of children with Autism being reported. And four years after our big pharma companies were able to send their vaccinations to China and they started following our exact vaccination schedule, China experienced a 3,000% increase in the reported cases of children with Autism. NOT Adults, but all new cases of CHILDREN with Autism and most at the tender age of 3-4 years old. Again, these are undisputed facts.

One more interesting tid-bit: Big Pharma imports over 50% of the products used or the medication that is already made from China: this, from the country that provided lead in our children's toys and deadly dog food and who knows what else is out there that has not been found YET.

See a connection here or is it just coincidence? Or am I being too factual for you?

Now, the following is just my opinion. Maybe you are correct that it’s not an epidemic. Because what would YOU call the blatant poisoning of our children and other countries children just to increase the value of your company so that you can buy the biggest ship , mansion, car collection..etc…etc… just in the name of profit.

The research is simple. Just look at who donates the largest to any politician. Why donate so much if you have nothing to hide or is it that they have a lot to sell and good legislation ignored?

It’s time you took off the blinders and became an advocate for your child.

OH! One more recent interesting thing that just happened. Why did the big Pharma companies just recall/remove all childhood OTC cold medications? What was the reason behind it? That’s an huge amount of profit lost in a very short period of time. Did big Pharm all of a sudden get a conscience and start caring about our children’s health? Or was it because something bigger is about to happen and they are trying to prevent even a larger profit loss? Only time will tell!

Anonymous said...

Thanks for your comment, Paul. I think your questions and the assumptions behind them deserve a more detailed answer than I can give here, so I will post about them later.

But the short version is: mercury poisoning is distinct from autism. That's a stone cold medical fact. That your research shows different points to the problem with much media coverage, the prevalence of misinformation on the internet regarding autism, and the agendas of some groups that deliberately mislead parents.

That's the real story, and I hope to rely on real evidence, not anecdote, to make my case. I look forward to you doing the same.

Ryans Dad said...

Ken,
I appreciate your comments and look forward to see how you approach this issue and what answers you come up with that is not based on the research that any pharmaceutical company or any research that was funded by them.

My research is about 10% internet based, 0% media based and 90% pure, nose to the grindstone, hard research.

I have a few friends who work in the bio-medical research field, hold masters degrees; PHD's in their respective fields and are working with grants in various areas of research.
None of them have given me info that would harm the corporations and/or colleges that they work for (and I would never ask them to either), but I have asked a lot of questions about the research that I have done and they have confirmed a lot of my research and facts.

None have denied that children with Autism are an epidemic.

Why would lawyers have an interest in this if there are not big corporation with big pockets to sue? Remember, they are all now protected under the terrorist act that the Bush administration signed into law in 2001/2002.

If I did this research full-time and was able to make a living from it, I would be able to get 90% supporting information about it by traveling to DC and other areas of the country. But I work two jobs just to pay for the therapies that my son gets. And the rest of the time I spend with my son teaching him, playing with him and working with him the best that I know how.

The one question that sticks in my mind and that no body can answer yet is what constituted the increase from 10 vaccinations to 33 in the late 80's? I grew up during that period of time and I do not remember any outbreak or national health crisis that occurred. And why are our children now given over 70 vaccinations?

It is the excessive increase of vaccinations that is now believed to be the trigger that has caused the epidemical increase of children with Autism.

I wish I could travel to DC, search their archives and get an answer to these simple yet complex questions.

Why vaccinate? I ask. Take a look at one of the healthiest society in America with no known cases of children with Autism, ADD, etc: The Amish.

I’m not trying to find a cure; I am trying to find the reason so that other parents and their children will not have to endure the anguish, exhaustion, pain, frustration and the weekly/daily meltdowns that tens of thousands people live with for a lifetime.

Anonymous said...

The Amish do vaccinate, and they are far from healthy. I'll post links to articles about a health clinic in Pennsylvania Amish country that reported a childhood seizure disorder that resulted in autistic-like symptoms and retardation. I've seen another study on vaccination rates in the Amish - they're higher than you think.

The homeland security bill protecting drug companies from vaccine related suits was introduced by Dick Armey, and later repealed. Lawyers are involved because even unfounded lawsuits can be costly.

The FDA ordered thimerosal removed from vaccines in 1999, not because of credible fears about its safety, but because unfounded fears can lead to a decline in vaccination rates. Baseless fears over MMR in the UK led to a measles outbreak a few years ago, resulting in needless deaths and lifelong injuries. Do we really want to see whooping cough and polio again?

If thimerosal causes autism, then why no decline in autism among today's 3-5 year olds? A spot check by the CDC in Jan., 2002 found only 1.9 percent of childhood vaccines in doctors offices still contained thimerosal.

Anonymous said...

Which of my points do you disagree with, anonymous?

Matt said...

When is this myth about the Amish going to be put to rest? The Amish do not have a religious restriction against vaccination. Many communities do vaccinate.

For those who don't vaccinate, they contract vaccine preventable diseases. This includes Rubella. One of the known environmental causes of autism is when a pregnant mother gets Rubella.

http://www.cdc.gov/mmwr/preview/mmwrhtml/00017145.htm

Lastly, they are a good and proud people. They are a part of us!!! They are Americans. Show them respect. Lancaster County is not a test-tube for research. Ask them before you try to pass laws requiring people to study them. It is just basic decency.

Here's another question! Have you ever researched what the effects of mercury poisening are? Interesting enough, I have. Most of all of it is the exact same symptoms of the symptoms of Autism.

Paul--did you look up the real symptoms or did you check the websites and the paper that purports to link the two? The real symptoms are nothing like autism. Nothing.

Matt

gottaxes? said...

There is nothing more moving than a parent seeking to protect, defend or improve their child. I too will do anything in the world, including lay down my life for the benefit of my children.

Having said that it should be obvious that it is as much an emotional commitment as it is a intellectual one. And emotional commitment's are notorius for clouding the truth even in the face of the obvious.

Do we really know what an 'autism epidemic' would look like? Do we have any reliable research to either define the prevalance of autism or define the threshold that would necessitate a label of 'epidemic'?

The truth of the matter is that NOBODY KNOWS, not parents, not the media, not the NIH, not researchers, NOBODY KNOWS the real numbers of people with ASDs today. 98%+ of the research that has been done has been done in anglo-centric environments. Yet two of the hallmarks of autism (social interaction, language delay) are clearly related to culture and likely impacted by culture as well.

So if we, for argument's sake use the number of 1 in 150 that is based on primarily Anglo research and apply it to all cultures and all countries and assume that prevalance doesn't change across cultures does it really tell us anything?

The closest thing to 'real' numbers are now coming out of a CDC-sponsored longitudinal research conducted at 14 centers in the US that show such wide variations as Alabama with 3.3 / 10,000 and NJ with 10.6/10,000. How can a blanket statement that prevalance across cultures doesn't change when prevalance within a culture is so widely divergent?

Only in the last year has research begun in Asian cultures on Autism Epidemiology. Study of the Epidemiology of Autism in Latin America needs to be undertaken as well. Only when we have scientifically-based insights into the incidence of autism across continents and cultures can we really begin to understand what these numbers mean and what level of alarm might be warranted.

The last thing a parent of a child with autism wants to hear is "we need to wait to get reliably information". This is why an enormous industry has sprouted promising cures and reversals that often do little more than cure the consumer of their finances. Yes more research needs to be done and it needs to be done quickly. If in fact we discover that the REAL incidence in Latin America is 432 in 10,000 and in Asia is 1.2 in 10,000 and in North America settles at 8 in 10,000 then we have some very promising opportunities to better understand and research the impact of genetics and environmentals on the expression of autism.

This will not happen quickly and cannot happen quickly enough for those affected by a diagnosis of autism.

Rather than invest emotional, psychological, intellectual and financial energy in a meaningless debate on whether an epidemic exists or not we might all be better off lobbying for more funding on basic research (1% of our energy) and focusing on legitimate interventions with reliable evidence that will have a beneficial impact on long-term outcomes for children with autism (ASD) (99% of our energy).

Just my 2 cents, now feel free to flame me.

/mike

Anonymous said...

Well I for one am not offended in anyway by what was orginally stated in this blog!!! Why??? Because I am the loving mother of 4 boys all on the spectrum. Yes you read that right....4 boys!!! So if any parent here should be over the top for the belief in an epidemic, it should be me right? I mean come on, don't I have a right to be totally ticked off at someone...anyone, about my childrens misfortune and fate in life??? Well, I'm not...it's senseless to "blame" anyone, or to even attack other's (including parent's) who have a different opinion!! Must I remind each and everyone of you here, that opinions are like ***holes, everyone's got one!!!

Why do I not hold to the vaccine theory? Because none of my children were exposed to Thimerasol....point blank!!! So now what? I can't blame that? So now who do I point my finger at, and take my anger and frustration out on??? Come one people...how useless is all the bickering amongst the very people, who are experiencing the same issues. Do I blame my husband, who displays all the symptoms and signs of Asperger's himself?? Do I blame my Father and my Brother, who also show signs of ASD??? Well DUH...no, I can't. Why, well because back in the day when those generations were going kids and going through school, they were just worthless, hyperactive, bad kids, who didn't pay attention in class, and spent too much time by themselves, and so on, and so on, and so on........does any of that sound familiar???

What's the point of arguing the points??? The fact is that Autism is here to stay. It isn't going anywhere, and I'd much rather they continue with research in ALL areas, and try to learn as much scientifically as they can about it. And we as parent's (or Aunts, Uncles, Grandparent's, etc.) should not spend so much time bickering about our conspiricy theories, and more time simply informing ourselves and everyone else in our lives, what Autism is, and how best to raise, manage, and live with our children, as happily as possible.

Our 4 boys are all over the spectrum, but they are all loved and cared for to the best of any families ability. I do as much research, studying, and learning as possible, to help my boys, and that does not include trying to find someone to blame for my boys' "affliction"....they are priceless.....however they are!!!

I am not here to debunk anyone's theories merely stating why they don't personally hold water in my life....is it an epidemic? Well, I'm not a scientist!!! I'll hold my decision for a time when I see more evidence....as I agree that with the current diagnoses rate, and the criteria for ASD has been changed so greatly over the last few years...that is a pretty logical point of view, and not one that I will simply toss aside.

And just a side note here...my family is taking part in the AGRE genetics study project, so that we may, in some small way, help facitlitate more understanding for researchers, who are doing their best to seek answer's, to so many angry questions.

Mother of 4 Autie boys...
Kelli

Anonymous said...

First of all, yes I do agree that a greater number of kids are being diagnosed due to the increased knowledge of the spectrum. This is a good thing. But, let's look at how our government agencies and as you said media define epidemic. Does anyone else recall when juvenile diabetes was all over the media and termed an epidemic? I do. Juvenile diabetes affects 1 in 500 and receives about $150 million in funding. The incidence of autism is 1 in 150 and it receives $15 million. See a problem? Not only that but the 1 in 150 are those with the autism disorder diagnosis...not all of those on the spectrum. So, those of us who have kids who are PDD-NOS or even Asperger's have more difficulty getting services for our children. Is it an epidemic? To me, the numbers don't lie.

Anonymous said...

I don't get your point. Epidemic has a specific meaning - it has nothing to do with how the media perceive it. And what does government funding for autism research have to do with the definition of epidemic?

You need to understand the difference between incidence and prevalence. Incidence is the rate over a given period of time. Prevalence is current incidence, plus past incidence, plus all the people who are autistic and haven't yet been diagnosed. There is zero evidence that the prevalence of autism is increasing to anything near epidemic proportions.

gottaxes? said...

My point is easily understood and simply stated: why argue over meaningless labels with emotional diatribes? The truth of the matter is nobody currently knows with any certainty the prevalance or incidence of this particular disorder.

I see two priorities: 1) funding research to truly understand these issues which will help us to discern etiology and perhaps better long term results for children affected; 2) make the most of currently available scientifically-based interventions to maximize quality of life.

The specific meaning of 'epidemic':
1. affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent.
2. extremely prevalent; widespread.
3. a temporary prevalence of a disease.
4. a rapid spread or increase in the occurrence of something:

my point here is: how many people define epidemic, what does 'extremely' prevalent look like, how 'rapid' is a rapid spread. There is no speicific meaning that defines how or when 'epidemic' gets applied to a particular condition, disease or disorder. Frequently it is the popular media that decides to use the label.

I do understand the difference between prevalence and incidence, although your definition misses the mark somewhat.

prev·a·lence:  The total number of cases of a disease in a given population at a specific time.

in·ci·dence: rate of occurrence or influence; especially : the rate of occurrence of new cases of a particular disease in a population being studied

Your final comment makes my point perfectly. Indeed there is no evidence and that is what we need to fund research for, to find out what the real numbers actually are.

Anonymous said...

"... nobody currently knows with any certainty the prevalance (sic) or incidence of this particular disorder."

The incidence is well known - it's the reported occurrence of new diagnoses. True prevalence is unknowable, since it includes all those diagnoses, as well as cases of autism that have never been diagnosed.

Epidemic is a scary word used with little justification when applied to autism. The definitions you offer do little to justify its use:

affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent

Autism is not contagious.

extremely prevalent; widespread

Too subjective.

a temporary prevalence of a disease

Again, there is no evidence that autism prevalence has ever changed

a rapid spread or increase in the occurrence of something

Not only subjective, but too easily applied to areas that have nothing to do with disease outbreaks. Is Iowa experiencing an epidemic of politicians? Did we see an epidemic of boy bands in the 1990s? When "epidemic" is so freely used, it starts to lose its original, specific meaning, so that its only purpose is to cause fear.

gottaxes? said...

I beg to differ. The incidence is NOT well know and is NOT the 'reported' occurrence. Incidence is the RATE of occurrence. A rate can only be determined by specific knowledge of the number of cases per x.

If all cases per x are not known or not diagnosed, or not diagnosed with the same criteria or are mis-diagnosed then reported incidence at best is a guess.

True prevalence can indeed be known as in the total number of cases in a GIVEN POPULATION at a GIVEN TIME. The prevalence of autism in March 2006 in the school district of Utomwa, IA is certainly knowable. The problem and confusion arises when neither time nor population is defined and the prevalance of a single school district in Utomwa, IA is presumed to be representative of global populations across large time periods.

The definitions I offered are stratight from the dictionary and are not selected to support and corrupt a particular point of view. I am not aware of any adjectives in our language that have been created to only apply to one specific condition. Rather the language needs to be used and understood in context.

Yes, one could argue, rightly that Iowa is experiencing an epidemic of politicians and this would be totally in keeping with it's dictionary meaning which I contend is not a specific and precise as you would like.

I do not ascribe intentions to those that use the word epidemic in connection with autism. I do suggest that it is typically used by the general media and not by the scientific community. I also argue that there is not yet sufficient evidence to reliably state incidence or prevalence in anything but extremely limited populations and timeframes.

We are essentially guessing based on very limited and often contradictory information. This, I aruge is what we need to focus on, obtaining scientifically valid data to inform the discussion and not resorting to word-smithing meaningless diatribes.

Anonymous said...

Theoretically, true prevalence can be determined, but think of the practical difficulties of obtaining such a number. You would need the same screening tool for a population, and carefully trained screeners. Even then you would have most likely have issues of intercoder reliability. If you had a significant number of subjects whose parents/caregivers/ guardians rejected participation in the study, it could throw off the study, and true prevalence would never be known.

Incidence is what is reported over a given time. If the numbers are invalid due to a change in diagnostic criteria, or different screening tools, or population shift, you still have a incidence.

If you track the incidence of autism and mental retardation over the last 20 years, you still one rate climbs as the other rate falls. I'll leave it to your imagination which rate does what.

Here's an excellent discussion of the "autism epidemic", and how whem it is understood in perspective, it doesn't look like an epidemic.

http://photoninthedarkness.com/?p=117