Plenty of research has shown that studies funded by drug or medical device companies are much more likely to produce results favorable to those companies’ products than studies funded by independent sources.
What has been less clear is whether the same holds true when the connection with the companies is not through direct funding of the studies, but through the financial ties of the studies’ principal investigators.
The reason why this has been such a vexing issue to figure out is due to the challenge of disentangling funding sources from financial ties. They often overlap.
Not only did the BMJ study discover widespread financial ties among the principal investigators of major drug studies, it also found that such ties are significantly associated with favorable results, even when the studies are not directly funded by the pharmaceutical industry.
These findings suggest that the evidence used to determine the effectiveness of medical treatments may have an even greater pro-industry bias than previously believed.
“Given the importance of industry and academic collaboration in advancing the development of new treatments, more thought needs to be given to the roles that investigators, policymakers, and journal editors can play in ensuring the credibility of the evidence base,” the authors of the BMJ study write.
Uncovering the ties
For the study, a team of researchers led by Dr. Salomeh Keyhani of the University of California, San Francisco, selected a random sample of 190 papers on 195 clinical trials published in 2013. They specifically focused on trials that tested the effectiveness of drugs because “these studies have a high impact on both clinical practice and healthcare costs.”
The researchers determined the outcome for each study (either positive or negative for the drug’s efficacy), and conducted a thorough search for financial ties among the study’s principal investigators, defined as the first author and senior author (last author) listed on the paper.
Financial ties included a variety of monetary payments, including consulting fees, speaker’s fees, honorariums, stock ownership and travel expenses.
Keyhani and her team found that more than half (58 percent) of the principal investigators of the 190 papers had financial ties to the drug industry.
Further analysis showed that 76 percent of the clinical trials with positive results had investigators with financial ties, compared to 49 percent of those with negative results.
That relationship held even after adjusting for such factors as funding source and sample size.
“One would expect industry to seek out researchers who develop expertise in their field; however, this does not explain why the presence of financial ties for principal investigators is associated with positive study outcomes,” Keyhani and her colleagues write.
Data should be public
It’s unlikely that all researchers are going to sever their financial ties to industry, at least any time soon. So, what can be done to minimize research bias associated with those ties?
In a commentary that runs with the BMJ study, Andreas Lundh of the University of Southern Denmark’s Center for Evidence-based Medicine and Lisa Bero of the University of Sydney, make these suggestions:
- Trial authors should share their data and participate in industry funded trials only if data are made publicly available.
- Reliable data on financial ties of authors should also be publicly available.
- Journals could help by rejecting research by authors who are unwilling to share their data and by penalising authors who fail to disclose financial ties.
- The role of companies in the design, conduct, or publication of the research should be transparent.
In the meantime, they add, “trials with industry funding or authors with financial ties should be interpreted with caution until all relevant background information is fully disclosed and easily accessible.”
FMI: The BMJ study and the accompanying commentary can be found on the journal’s website.