Sunday, February 12, 2012

The tricks that drug companies do contd. - Jon Jureidini explains citation distortion

Most people are now aware how the academic literature on medications is undermined, (perhaps fatally for some drug classes such as antidepressants [1]), by publication bias and selective reporting. To these, we must now add citation distortion or “unfounded authority”. Unfortunately, much consensus in psychopharmacology is based on unfounded authority.

Citation distortion [2,3] is the process whereby, in a field with ambiguous primary data, studies showing the desired outcome are preferentially cited. Over years and generations of reviews, this distortion is amplified with exponential increases in supportive citation, facilitated by increased citation of papers that do not contain primary data (ie, one review cites another). At the same time, there is no parallel increase in citation of critical reviews.

Errors accumulate in this process of reiterative citation; for example what is acknowledged as hypothesis in cited articles is misrepresented as fact in reviews.

An example from this week’s academic literature is an article from Australia’s MJA [4]. Amongst the numerous self-citations (count them), note the disingenuous citation of the discredited Gibbons et al paper (see David’s blog at as though it supported ‘The importance of managing anxiety and depression in young people to minimise functional, medical and psychological complications’.

[1] Ioannidis JP. Effectiveness of antidepressants: an evidence myth constructed
from a thousand randomized trials? Philos Ethics Humanit Med. 2008 May
[2] Greenberg S. How citation distortions create unfounded authority: analysis of a citation network. BMJ2009;339doi: 10.1136/bmj.b2680 (Published 21 July 2009)
[3] Slawson DC, Shaughnessy AF. Obtaining useful information from expert based sources. BMJ. 1997;314(7085):947-9.
[4] Scott EM et al. Targeted primary care-based mental health services for young Australians. MJA 2012; 196: 136-140

Posted via email from Jack's posterous

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