The article didn’t say much (anything?) about the relationship between MMR and autism, that all came about in a press conference that was done before (I think) the article came out – but then people think that’s what the article was about, because that’s what they were told in the press conference.
Vaccination rates might have plummeted anyway – there are plenty of people who rant about them, and they don’t seem to rely on evidence of any sort, so the publication of an article only helps a little.
Another article that I can recall that had a large effect was the Kellogg’s diet article, from (I’d guess) about 10 years ago, I can’t find it now but at the time they said that the number of downloads was in the moderate 6 figures. I don’t know if sales of Kellogg’s cereals increased.
Oh, I’ve just thought of another and I’m too lazy to edit what I’ve already written. The 1995 pill scare paper (also published in The Lancet), which said that there was an increase in risk of thrombosis in women taking the contraceptive pill. I’ve used this in my teaching in the past, ‘cos it’s a nice example of relative versus absolute risk differences (i.e. double the risk is an increase of 0.001% – or something). There are several papers I’ve seen that look at the repercussions – here’s one: http://www.bmj.com/cgi/reprint/326/7383/254.pdf .
One interesting feature that potentially increases the possibility of journals having an impact in the UK is that The Lancet and the BMJ are published on a Friday, so news stories have the weekend to get disseminated through the media before medical professionals (either govt or people’s own doctors) can comment on them. I used to set a task for students which was to find the Friday Health Scare, which was usually pulled from one of those two journals, and said “X causes cancer: or “Y cures cancer”.
There’s a Scott Adams quote I like: “Reporters are faced with the daily choice of painstakingly researching stories or writing whatever people tell them. Both approaches pay the same.”
Andrew Gelman reflects on Lancet’s retraction of measles vaccination-autism paper, good points, worth reading. I think it’s interesting on a couple of points. First, while publication of an article might not by itself influenced plummeting measles vaccination rates, it’s possible that this research when quoted in newspapers, might have validated claims that would otherwise be dubbed as unsubstantial. How influential might that be? Second, I quite liked the way he relates day of the week release of new articles and their dissemination into public domain before a more reasoned, possibly decision-modifying discussion about the story gets to appear. Something worth thinking about. I think I am going to use the pill scare paper this year for demonstrating the difference between absolute risk difference and relative risk estimates. That was a great example to point out. Learning point.