Research published on bmj.com today says that almost all (94%) of the scientific authors who provided positive results for the anti-diabetic drug rosiglitazone had financial relationships with pharmaceutical companies.
While the study acknowledges that financial relationships may not necessarily be the reason for positive research results, it concludes that further reform is needed to ensure trust in scientific work.
In 2007, a large scale review of rosiglitazone showed that use of the drug led to a significant increased risk of heart attacks. This in turn led to further studies and commentaries by scientists about the safety of rosiglitazone. Policies were also developed to encourage disclosure of such financial conflicts of interest.
But whether these policies have made any impact on the association between financial conflicts of interest and views expressed in scientific reports is still unknown.
So researchers at the Mayo Clinic in the USA assessed over 200 articles on rosiglitazone to explore a possible link between authors' financial conflicts of interest and their views on the safety of the drug.
They found that almost half of the study authors (45%) had financial conflicts of interest and almost a quarter of these (23%) did not disclose this information. Three studies included in the latter group published a statement declaring no conflicts of interest.
Almost all (94%) authors who had favourable views on the safety of rosiglitazone were more likely to have a financial conflict of interest with a pharmaceutical company than were authors who had unfavourable views.
The researchers conclude by saying: "Disclosure rates for financial conflicts of interest were unexpectedly low, and there was a clear and strong link between the orientation of authors' expressed views on the rosiglitazone controversy and their financial conflicts of interest with pharmaceutical companies."
"These findings, while not necessarily causal, underscore the need for further progress in reporting in order for the scientific record to be trusted," they add.