Poul Thorsen MD Phd
N Engl J Med. 2002 Nov 7;347(19):1477-82.
A population-based study of measles, mumps, and rubella
vaccination and autism.
Danish Epidemiology Science Center, Department of Epidemiology
and Social Medicine, Arhus, Denmark. email@example.com
BACKGROUND: It has been suggested that vaccination against measles, mumps,
and rubella (MMR) is a cause of autism. METHODS: We conducted a
retrospective cohort study of all children born in Denmark from January 1991
through December 1998. The cohort was selected on the basis of data from the
Danish Civil Registration System, which assigns a unique identification
number to every live-born infant and new resident in Denmark.
MMR-vaccination status was obtained from the Danish National Board of
Health. Information on the children's autism status was obtained from the
Danish Psychiatric Central Register, which contains information on all
diagnoses received by patients in psychiatric hospitals and outpatient
clinics in Denmark. We obtained information on potential confounders from
the Danish Medical Birth Registry, the National Hospital Registry, and
Statistics Denmark. RESULTS: Of the 537,303 children in the cohort
(representing 2,129,864 person-years), 440,655 (82.0 percent) had received
the MMR vaccine. We identified 316 children with a diagnosis of autistic
disorder and 422 with a diagnosis of other autistic-spectrum disorders.
After adjustment for potential confounders, the relative risk of autistic
disorder in the group of vaccinated children, as compared with the
unvaccinated group, was 0.92 (95 percent confidence interval, 0.68 to 1.24),
and the relative risk of another autistic-spectrum disorder was 0.83 (95
percent confidence interval, 0.65 to 1.07). There was no association between
the age at the time of vaccination, the time since vaccination, or the date
of vaccination and the development of autistic disorder. CONCLUSIONS: This
study provides strong evidence against the hypothesis that MMR vaccination
causes autism. Copyright 2002 Massachusetts Medical Society
PMID: 12421889 [PubMed - indexed for MEDLINE]