By Professor Brian Hooker
Of all of the papers I have reviewed over my 26-year career as a research scientist, the Destefano et al. 2013 J. Peds. article describes perhaps the most flawed and disingenuous study I have encountered.
The basis for the study is essentially a rehash of the data that was used to generate the Price et al. 2010 Pediatrics study (Price et al. 2010 “Prenatal and Infant Exposure to Thimerosal From Vaccines and Immunoglobulins and Risk of Autism” Pediatrics 126:656) that was supposed to be the CDC’s “final word” stating that thimerosal, the mercury-containing preservative in some vaccines, was in no way causally linked to autism. Not only was this original study fatally flawed due to a statistical error called “overmatching” (which I’ll discuss further below) but also the study authors hid data regarding the only valid part of the study (i.e., prenatal thimerosal exposure) which showed that children exposed to just 16 microgram mercury in thimerosal in utero were up to 8 times more likely to receive a diagnosis of regressive autism (Price C, et al. Thimerosal and Autism. Technical report. Vol I. Bethesda, MD: Abt Associates Inc; 2009).
The statistical model within the Price et al. 2009 report was run in 6 different ways. The most robust models (showing an interaction parameter between prenatal and postnatal thimerosal exposure) were run in three of the six iterations.