Reviewing the Autism Prevalence (The Use of the California Department of Disability Statistics)

This subject has already been discussed in great detail by Autism Diva (2005) and can be found here http://autismdiva.blogspot.com/2005/04/california-dds-responds-very.html and here http://autismdiva.blogspot.com/2005/07/this-just-in.html. My comments then, should only serve as reminders.

Autism Diva (2005) wrote to the an official in the California Department of Disability Services (DDS) and displays the email from that person. The email indicates in no uncertain terms that the DDS data should not be used to track autism prevalence (Autism Diva, 2005).

The letter indicates that it is inaccurate to label the change between given quarters as “new intakes”. This is due to change in service categorization (Autism Diva, 2005). This is comparable to what occurs in the IDEA data sets; we are dealing with a assignment to service categories rather than strict descriptive label.

Based on these data, Autism Diva (2005) went on to calculate the prevalence of autism via the DDS system at 1 per 321, which like the IDEA data is discrepant from what is established in the epidemiology.

For additional interesting and problematic use of the DDS data please see Gernsbacher, Dawson, & Goldsmith (2005). That article can accessed here http://www.psychologicalscience.org/pdf/cd/autism_epidemic.pdf

References

Autism Diva. Monday, July 11, 2005. http://autismdiva.blogspot.com/
Accessed October 6, 2005

Autism Diva. Friday, April 22, 2005. http://autismdiva.blogspot.com/
Accessed October 6, 2005

Gernsbacher MA, Dawson M, & Goldsmith HH. (2005).Three reasons not to believe in an autism epidemic.Current directions in psychological science, 14 (2), 55-58.