Incidence of Autism
In the media and in other sources there is concern that the incidence of autism and autistic-spectrum disorders has increased dramatically. The idea has been unchallenged in the literature until now. In a very lucid article, Dr. Eric Fombonne (Institute of Psychiatry , London University), questions the available evidence for that claim. To being with, he points out that the cases in question are usually referred cases, which suggests that one is talking about an increase in treated cases, earlier identification, and a sheer increase in population in centers where this has been reported, like in California. Dr. Fombonne carefully reviews a number of fallacies and biases in a widely quoted report from the California Department of Developmental Services, which is one of the centerpieces of the claim about the increased incidence of autism. Together with other reports reviewed in his brief article, the author demonstrates that there is no scientific basis to conclude that there is such increased incidence. He does not say that there is no increase, but simply demonstrates that the evidence used to make the claim of increased incidence is non-existent. Among other things, the article makes one reflect on the lack of sophistication of most professionals (including ego) reading scientific literature, not only regarding epidemiology, but statistical analyses, etc., so the claims are often taken “on faith”. This is a refreshing reminder that the “devil is in the details”.
Fombonne, E. Is there an epidemic of autism? Pediatrics. Feb 2001. Vol.107. No.2. pp. 411-412.