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Financial ties between researchers and drug industry linked to positive trial results

Selective outcome reporting, lack of full data publication and inappropriate analyses could be to blame

Ingrid Torjesen

Wednesday, 18 January 2017

Financial ties between researchers and the companies that make the drugs they are studying are independently associated with positive trial results, suggesting bias in the evidence base, concludes a study* published by The BMJ.

A team of US based researchers set out to investigate the association between financial ties of principal investigators and study outcomes in a random sample of 195 drug trials published in 2013. They focused on trials that examined the effectiveness of drugs, because these studies have a high impact on both clinical practice and healthcare costs. More than half (58%) of principal investigators had financial ties to the drug industry - including travel expenses, honorariums, payment for advisory work, or stock ownership.

The results show that trials authored by principal investigators with financial ties to drug manufacturers were more likely than other trials to report favourable results. Even after accounting for factors that may have affected the results, such as funding source and sample size, financial ties were still significantly associated with positive study outcomes.

The authors suggest potential mechanisms linking industry funding, financial ties, and trial results could include selective outcome reporting, lack of publication, and inappropriate analyses. They said: "more thought needs to be given to the roles that investigators, policy makers, and journal editors can play in ensuring the credibility of the evidence base."

In a linked editorial,** Andreas Lundh from the University of Southern Denmark and Lisa Bero from the University of Sydney, urged trial authors to share their data and participate in industry funded trials only if data are made publicly available. They said that journals should consider rejecting research by authors who are unwilling to share their data and penalising authors who fail to disclose financial ties, and that the role of sponsors, or companies with which authors have ties, in the research must also be transparent.

In the meantime, trials with industry funding or authors with financial ties "should be interpreted with caution until all relevant information is fully disclosed and easily accessible," they concluded.

* Ahn R, Woodbridge A, Abraham A, et al. Financial ties of principal investigators and randomized controlled trial outcomes: cross sectional study. BMJ 2017;356:i6770. DOI: 10.1136/bmj.i6770

** Lundh A, Lisa Bero L. The ties that bind. BMJ 2017;356:j176. DOI: 10.1136/bmj.j176

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