New study fails to find link between MMR and autism

Abstract

A new study published in the British Medical Journal failed to find any temporal link between the rise in autism and the prevalence of MMR vaccine usage. The report, based on a time trend analysis of data from the UK general practice database, studied children aged 12 or younger diagnosed with autism in 1988–1999, with further analysis of boys aged 2–5 years born between 1988 and 1993. They found that the rate of autism rose sevenfold from 0.3 cases per 10 000 people per year to 2.1 cases per 10 000 people per year. Analysis of 2–5-year-old boys born between 1988 and 1993 showed that the rate of autism quadrupled, whereas the prevalence of MMR vaccination remained stable at over 95%. Lead author Dr James Kaye, of the Boston University School of Medicine, concludes that, ‘…because the incidence of autism among 2–5-year-olds increased markedly among boys born in each year separately from 1988 to 1993, while MMR vaccine coverage was over 95% for successive annual birth cohorts, the data provide evidence that no correlation exists between the prevalence of MMR vaccination and the rapid increase in the risk of autism over time.’ The authors suggest that increase in recorded diagnoses of autism could be caused by increased awareness of the condition among parents and general practitioners, changing criteria or environmental factors. Br. Med. J. (2001) HM