The pharmaceutical industry has previously been accused of failing to submit all clinical trials data for publication, particularly if the results are unfavourable for the drugs in question. However, a recent study published in the British Medical Journal found no evidence of submission or publication bias.

Evoniuk and co-workers, who are employees or past employees of GlaxoSmithKline (GSK), compiled a list of all human drug studies completed by GSK over a 6-year period (2009 to 2015), and noted whether the results of each study had been submitted to a peer-reviewed journal. Individuals blind to the submission/publication status of the trials then rated them as either ‘positive’ (favourable for the study drug), ‘negative’ (perceived to be unfavourable for the study drug), ‘mixed’, or ‘non-comparative’.

Of the 1064 trials identified, 904 (85%) had been submitted as a full manuscript by the study cut-off date of February 2016, and a further 77 (7%) had been written up as conference abstracts. Studies with positive outcomes were less likely to have been submitted for publication than studies with negative outcomes (79% versus 92%). While the rate of acceptance at first submission was slightly higher for studies with positive outcomes (56% versus 48%), overall publication rates by the cut-off date were higher for studies with negative outcomes (77% versus 66%).

This study examined data from only a single pharmaceutical company. Nevertheless, the authors argue that the results ‘provide a clear signal that submission and publication bias against studies with negative outcomes might be less widespread than has generally been assumed and should not deter efforts to publish them’.

——————————————————–

Summary by Louisa Lyon, DPhil from Aspire Scientific