Blog Ipsa Loquitur

A new study has found that a ten year old study was correct, and that most new studies are wrong. No, really:

The claim that “most published research findings are false” is something you might reasonably expect to come out of the mouth of the most deluded kind of tin-foil-hat-wearing-conspiracy-theorist. Indeed, this is a statement oft-used by fans of pseudoscience who take the claim at face value, without applying the principles behind it to their own evidence. It is however, a concept that is actually increasingly well understood by scientists.

It is the title of a paper written 10 years ago by the legendary Stanford epidemiologist John Ioannidis. The paper, which has become the most widely cited paper ever published in the journal PLoS Medicine, examined how issues currently ingrained in the scientific process combined with the way we currently interpret statistical significance, means that at present, most published findings are likely to be incorrect. […]

Last year UCL pharmacologist and statistician David Colquhoun published a report in the Royal Society’s Open Science in which he backed up Ioannidis’ case: “If you use p=0.05 to suggest that you have made a discovery, you will be wrong at least 30 percent of the time.” That’s assuming “the most optimistic view possible” in which every experiment is perfectly designed, with perfectly random allocation, zero bias, no multiple comparisons and publication of all negative findings.

Read the whole article. The evidence is impressive, and meticulously footnoted.