CDDS Autism Zombie
What is more, this zombie seems impervious to attack. If the data indicate a continued rise, this is proof that vaccines cause autism and even though much of the thimerosal has been removed, there is still some being used in the flu vaccines and this is the likely culprit. But, if the numbers drop, this is also proof that the vaccines cause autism, because the sudden drop can be correlated to the not quite complete removal of thimerosal.
I should say that some take a more reasonable approach. They accept the criticism that these data are not meant to be used for epidemiology. However they then argue that it is the best that can be had. And that if one sees trends here, even if the data are flawed, this is still indicative of an actual effect. This argument is actually somewhat widespread.
But the argument is still flawed. If one refers to the graph, it should be clear that the natural statistical variation allows for an occasional decrease; even one extending for a few quarters before an uptake is noted. That is the nature of statistics; one is going to see an occasional slight downswing. Moreover, the fact that the CDDS data are so regular does not make them reliable or valid.
The CDDS uses a form version from 1986. It has the following categories.
0 = 'None''
The form counts the 1’s and 2’s. These categories are not part of DSM-IV-R. They are older categories based on earlier ideas. Thus, it can not be correctly said that CDDS offers services only to Autistic Disorder as defined by the DSM-IV. Full syndrome includes both PDD-NOS and Autistic Disorder.
These data are not good measures of Autistic Disorder, as they have been advertised by some persons, almost unceasingly. Moreover, there are no reliability checks conducted to make sure the State diagnosticians are conforming to recommended practices. This makes them an unreliable and invalid, source of autism data. For these reasons any attempt to use these data for purposes of epidemiology is ill-founded.