2009-07-22

Distortions, biases, amplification and invention in the biomedical literature.

The telephone game that many of us played as children showed the amusing side of how indirect communication can lead to distortion of the original message. Steve Greenberg has written an eye opening article in the British Medical Journal describing how he followed the entire citation network for a particular claim (that β amyloid, a protein accumulated in the brain in Alzheimer’s disease, is produced by and injures skeletal muscle of patients with inclusion body myositis) that in a medical analog of the telephone game resulted in the subsequent adoption of questionable "facts" as medical conventional wisdom. He also shows how, much like websites trying to increase their Google Pagerank, there arise mutual citation networks that will increase the acceptance of their joint claims. One of the lasting contributions of this study is the development of a vocabulary of citation distortions (reproduced below) that Greenberg used to taxonomize the citation network. It also is a vocabulary that other conscientious reviewers and readers can use in their own disciplines to identify and name these distortions.

Vocabulary of citation distortions

Citation

Both scholarly and social forms: the scholarly form connects statements to the broader

medical literature, the social form (social citation) includes self serving and persuasive

subtypes

Citation distortions

Self serving citation is always a distortion

Persuasive citation may be necessary to communicate new, sound claims to the scientific

community; it may, however, have distorted uses—citation bias, amplification, and

invention

Citation bias

Systematic ignoring of papers that contain content conflicting with a claim

Bolster claim; justifying animal models to provide opportunities to amplify claim

Amplification

Expansion of a belief system without data

Citation made to papers that don’t contain primary data, increasing the number of

citations supporting the claim without presenting data addressing it

Invention

Citation diversion—citing content but claiming it has a different meaning, thereby diverting

its implications

Citation transmutationthe conversion of hypothesis into fact through the act of citation

alone

Back door invention—repeated misrepresentation of abstracts as peer reviewed papers to

fool readers into believing that claims are based on peer reviewed publishedmethods and

data

Dead end citation—support of a claim with citation to papers that do not contain content

addressing the claim

Title invention—reporting of “experimental results” in a paper’s title, even though the paper

does not report the performance or results of any such experiments