Retracted studies ‘contaminate’ 157 clinical practice guidelines, BMJ study finds

Some of the junk studies are so bad 'even a blind cow can see it', says Professor Ben Mol.

Every retracted study may influence the results of three systematic reviews, each of which subsequently infects three clinical practice guidelines, researchers warn.

Writing in The BMJ, they say this “contamination chain” means junk science influences doctors long after it is identified and called out.

The researchers, from the University of Queensland, Bond University and others, said removing the results of retracted studies from meta-analyses completely reversed their conclusions in 4% of cases.

In more than 8% of cases, it changed the direction of an effect, and in 16% of cases, it flipped whether the effect was statistically significant or not.