Correspondence Jan 2000
- Vaccine Affect
- 15 hours ago
- 2 min read
Altmann wanted to know a little more detail about the first two analyses in Taylor et al study “Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association.”
For their first analysis, “Taylor and colleagues state children born before 1987 were also eligible for MMR vaccination, albeit after their second year of life. I have not been able to deduce from the numbers presented how many of the 109 study children born before 1987 received MMR vaccine.”
As regards the second analysis, “research by the National Autistic Society found that 40% of parents wait more than 3 years for a diagnosis. Indeed, Taylor and colleagues allude to delays in diagnosis. (..) Although the variable age at parental concern is heavily prone to bias, use of age at diagnosis in this context may introduce an important bias in the opposite direction (ie, towards obtaining a negative finding).”
Autism and measles, mumps, and rubella vaccine
Altmann, Dan
The Lancet, Volume 355, Issue 9201, 409
Authors' reply
“Altmann is correct in noting that some children born before 1987 received MMR vaccine.”
36 children in our cohort born before 1987 received MMR vaccine. “Age at parental concern was recorded in 29 of these; in all cases this was before MMR vaccination was given.”
“We agree with Altmann that there may be delay in the diagnosis of autism. We have undertaken a further analysis, as Altmann suggests, of age at parental concern by vaccine group.”
Out of 498 autistic children that were selected for this study, 244 cases were restricted to this analysis with age at parental concern between 15 months and 48 months.
108 received MMR vaccine before the age of 15 months
88 at 15 months or later
48 did not receiving MMR vaccine
Taylor, Brent et al.
The Lancet, Volume 355, Issue 9201, 409 - 410
