My Google homepage displays rotating quotations from well-known public figures.
Last week, I read that famed American astronomer Carl Sagan once said: “Extraordinary claims require extraordinary evidence.”
This quote resonated with me as particularly insightful.
A few minutes later, I read a news item from the British Medical Journal accusing pediatric gastroenterologist Dr. Andrew Wakefield of fraud in his 1998 research findings linking autism to the measles, mumps and rubella (MMR) vaccine.
The Sagan quote rang true with crystal clarity. Wakefield’s report in the widely read journal Lancet was certainly an extraordinary claim, the kind that Carl Sagan would have thought required extraordinary evidence.
Unfortunately, there was no extraordinary evidence in this case. In fact, it appears the evidence was fraudulent.
The Wakefield manuscript described 12 children with mild intestinal inflammation and autism-like developmental regression, all occurring in a time frame shortly after receiving the MMR vaccine.
There was no proper control group, and the number of study subjects was small. Important observations were not made in a blinded fashion. Notwithstanding, the study was published in a reputable medical journal.
Although Wakefield characterized the MMR vaccine as a “possible environmental trigger” in the conclusion of his research paper, the damage was done. Media attention heightened public awareness of an extraordinary claim.
In the aftermath of the report, alarmed parents chose to forgo vaccination for fear that their children could develop autism. MMR vaccination rates dropped substantially. Mumps and measles outbreaks became commonplace.
In the years since the 1998 publication, millions of dollars have been spent investigating a link between the MMR vaccine and autism using more-robust study designs. None has been found.
Wakefield’s work has been scrutinized intensely. Last year, the Lancet formally retracted the 1998 article, citing scientific and ethical irregularities (one can still read the article online, with the word retracted ominously crossing the page in large, red capital letters).
And this month, the British Medical Journal published an article formally accusing Wakefield of fraud.
In the case of a link between autism and MMR, an extraordinary claim was made in the absence of extraordinary evidence. It fact, the evidence was probably fraudulent. In principle, this is similar to falsely shouting fire in a crowded theater, only worse.
Millions of dollars have been spent disproving any link between autism and MMR, dollars that could have been used to pursue meritorious autism research. Thousands of children have suffered with preventable and potentially fatal childhood diseases because vaccinations were not given.
When a research report makes an extraordinary claim, especially one that has serious public-health implications, medical journals and the peer reviewers they use must raise the bar, taking care to demand extraordinary evidence.
Similarly, the news media should scrutinize and report extraordinary claims in a more-detailed, rigorous and responsible manner. Doing so will most certainly reduce the likelihood of regrettable events such as this saga.
Used with permission from The Columbus Dispatch – originally published 1.23.2011
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|Dr. John Barnard physician and scientistRead more posts from Dr. Barnard|