Dr. Offit said the study authors reach erroneous conclusions due to an erroneous definition of autism. A child with measles encephalopathy, he said, may have severe cognitive deficits that fall into the autism spectrum, but such symptoms themselves do not necessarily translate into a diagnosis of autism.The good doctor is of course talking about the recent paper that purports to show that autism might be more common in children compensated by the the so-called vaccine court than in the general population. While I don't yet have much of an opinion on the paper, I do know that Dr. Offit's statement is just plain wrong.
First and foremost, a diagnosis of autism is based solely on the presence or absence of behaviors. If you have enough of the behaviors of autism then you have autism, if you don't then you don't. There is absolutely nothing in the definition that says anything about the underlying causes of the behaviors. It is factually inaccurate to say that "severe cognitive deficits that fall into the autism spectrum" aren't autism. Autism is autism - regardless of the cause.
Second, the authors in the paper actually used a validated autism screening test called the Social Communication Questionnaire (SCQ) with twenty-two of the children that they found. While the test cannot definitively show that a person has a diagnosis of autism, it is certainly not an "erroneous definition of autism". As a matter of fact, there are a quite a few research studies that have used the SCQ to help identify cases of autism
The problem is that Dr Offit has painted himself into a corner in regards to autism and vaccines. He regularly says things such as "This hypothesis has been tested thoroughly. The question has been asked and answered.", as he did in this story. He has written several books on the subject, all of which basically say the same thing - no relation between autism and vaccines.
I don't think he is now able to admit, either to himself or publicly, that he might have been wrong. Instead he has to come up with non-autistic forms of autism and spends his time "defending" his idea against anyone who questions it.
This is precisely the reason why there is no such thing as an "asked and answered" question in science. Once you have decided that you already have the answer you stop listening to what everybody else is saying.