Anatomy of an epidemic

When you hear claims of an epidemic — of obesity, type 2 diabetes or whatever — have you ever stopped to critically question if they’re really true?

The news is filled with alarming statistics, nonstop images of the most extreme examples, and rhetoric that becomes more frantic with each passing day. How many epidemics are we told are now reaching “pandemic proportions” and that we must save the children?

Hearing the word “epidemic,” let alone “pandemic,” leads us to instantly think of danger and crisis. It’s easy to believe the claims, repeat them or, worse, act on them without knowing if the information is even correct. It never occurs to most of us to even consider that an epidemic can be created and not be due to anything ominous at all.

What if you learned that most scientists don’t see an epidemic of obesity or type 2 diabetes, but that the evidence shows very modest increases in actual numbers and that what really is at work is an epidemic of diagnosis, with a hefty dose of marketing spin?

A study released in the journal of the American Psychological Society in 2005 provides an invaluable insight into how an epidemic is created and how public perceptions can become completely disconnected from the scientific evidence. The parallels between the epidemic they chose to examine for their study and the epidemics of obesity, diabetes and others are remarkable and can help us begin to think critically and see past epidemic hype. So, as you read this study, keep other popularized epidemics in mind. Later, we’ll come back and begin to put the pieces together.

Researchers at the University of Wisconsin-Madison and the University of Montreal-Quebec, Canada examined the scientific evidence behind an epidemic of autism that mainstream media was calling mysterious and frightening and that new cases were “exploding in number.” What they found was that more people were fitting into the current criteria for autism — not because there was more autism but because:

· the diagnostic criteria had been purposely broadened

· public awareness had been deliberately increased through effective marketing, and

· greater lengths were being intentionally taken to identify cases

“The phenomenon of autism has existed most likely since the origins of human society,” they wrote. Autism didn’t exist as a diagnosis, however, until the 1940s when a constellation of differences that had always existed in the population came to be named “autism.” But it wasn’t until 1980 that autism was first added to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) using six mandatory criteria. Most of the cases in this first tightly-defined criteria had severe associated problems. But over the years those criteria underwent several changes, each one widening the definition to include more subthreshold symptoms and milder variations. The most recent DSM-IV has 16 criteria, only half of which need to be met to be diagnosed autistic. The evidence shows that it’s these mild variants that now account for most of the currently diagnosed cases, they found. They added:

Consider also the recent practice of codiagnosing autism alongside known medical and genetic conditions (e.g., Down syndrome, Tourette’s syndrome, and cerebral palsy); the contemporary recognition that autism can exist among people at every level of measured intelligence, the deliberate efforts to identify autism in younger and younger children, and the speculation that many individuals who would meet present-day criteria were previously mis- or undiagnosed, including some of the most accomplished, albeit idiosyncratic, historical figures such as Isaac Newton, Lewis Carroll, W.B. Yeats, Thomas Jefferson, and Bill Gates.

Most crucial to understand, they cautioned, is that “broadening the criterion will result in a dramatic increase in diagnosed cases.” They illustrated how simply lowering the cutoff for the definition of “tall” from 6’-2” to 6’ a decade later would create a 27.3% surge in the cases of tall males — without any real increase in height among a population of men. Similarly, they found that the broader definition for autism alone could explain the 27.3% increase in California children receiving labels of autism from 1987 to 1998. When the earlier criteria was applied for all the years, there was no clinically significant difference.

A surge in perceived cases, coupled with growing media attention to the mysterious increases, led to legislation being introduced, research being funded, and school and medical resources being mobilized to identify and report more cases so as to ensure that children were made eligible for new special programs. “Child count” screenings and reporting were made mandatory and the data further “used as supportive evidence of an autism epidemic.” They exampled a message that was distributed in October 2003 by the Autism Society of America, saying: ‘‘Figures from the most recent U.S. Department of Education’s 2002 Report to Congress on IDEA [Individuals With Disabilities Education Act] reveal that the number of students with autism [ages 6 to 21] in America’s schools jumped an alarming 1,354% in the eight-year period from the school year 1991-92 to 2000-01.’’ [emphasis added]

What the Autism Society failed to reveal, they said, was that the Report to Congress had included this note: “Prior to the 1991–1992 school year, there was no child count of students with autism; autism did not even exist as an IDEA reporting category. Moreover, in 1991–1992, use of the autism reporting category was optional (it was required only in subsequent years).”

A very common and easy mistake to make is to think “diagnosis” means actual disease. As was discussed in an earlier post, more screening leads to more diagnosis — that is not the same thing as more disease. It’s the ‘seek and ye shall find’ principle. Such an epidemic is “an epidemic of diagnoses.”

But there are larger reasons for the popularity of epidemics. Cries of “epidemic” bring in more money — for research; for foods, products and programs to identify and address the epidemic; and for “health” initiatives to prevent the epidemic. Cries of “epidemic” bring more stature to one’s research; academic and government promotions; votes for political office and support for one’s programs; invitations to speak and sit on important committees; book sales; and more notice and prominence to one’s agency, program, institute, publication or foundation.

“Epidemics solicit causes; false epidemics solicit false causes,” said the researchers.

If there is no real epidemic, then there is also nothing to blame — no child or parent, person, food, lifestyle, big corporation or environmental evil. Speaking out against an epidemic is a very unpopular thing to do as it goes against a lot of vested interests dependent on that epidemic, as these authors discovered, and few are willing to do so.

The researchers ask readers to consider the harm resulting from cries of an epidemic. What message is being sent to children and adults when their increasing numbers are called an epidemic, a pandemic, a scourge? It’s not advocacy, helpful or healthful. True scientific inquiry, medical advances, and our compassion need not be lessened by following scientific reasoning and acknowledging there is no epidemic.

Lead author, Dr. Morton Ann Gernsbacher at the University of Wisconsin has made their paper, “Three Reasons Not to Believe in an Autism Epidemic,” available free at her website, here. She and Dr. Hill Goldsmith are parents of an autistic child and the third research associate, Michelle Dawson at the University of Montreal, is autistic.

© 2007 Sandy Szwarc

Addendum: Their article is merely used as an illustration of an excellent portrayal of the creation of an epidemic, but autism is not the focus of this blog. For discussions on autism, please refer to bloggers devoted to this issue, such as Autism Diva and Autism Street.