A new US study published this week that investigated the research behind the anti-diabetes drug rosiglitazone (GlaxoSmithKline’s Avandia) found that nearly all the scientific authors who provided results in favour of the drug had financial relationships with pharmaceutical companies, and while this may not prove industry’s interests influenced the research, it suggests a need for greater disclosure of financial relationships to increase trust in scientific work said the authors.
You can read about the study by Dr Amy T Wang and colleagues from the Mayo Clinic, Rochester, Minnesota, in the 18 March online issue of the BMJ.
In a cross-sectional systematic review of the published literature, Wang and colleagues found a strong link among authors between favourable views on the safety of the anti-diabetic drug rosiglitazone and financial conflicts of interest with companies that make rosiglitazone, pioglitazone, and any antihyperglycaemic agents (drugs that bring down blood sugar).
They found that 94 per cent of the authors of papers that gave a positive view of rosiglitazone with respect to cardiovascular risk had financial relationships with pharmaceutical companies.
Wang and colleagues wrote that while their findings don’t necessarily show that financial conflict of interest directly caused the positive views, they stressed the need for more transparency about researchers’ financial links with industry so people can trust their work.
In 2007, a large scale review of the anti-diabetic drug rosiglitazone (marketed by GlaxoSmithKline GSK under the brand name Avandia) found that the drug increased the risk of heart attacks. This opened a debate among scientists about its safety, and prompted harsh criticism from a US Senate committee.
According to report earlier this month in the Guardian newspaper, analysts at UBS estimate that GSK’s liability from personal injury lawsuits over Avandia could be between 1 and 6 billion US dollars.
The BMJ authors said at the same time as the 2007 review, policies were also developed to encourage more transparency about financial conflicts of interest, but we know little about how effective they have been.
For their study they assessed possible links between authors’ financial conflicts of interest and their views on the safety of rosiglitazone in over 200 scientific papers.
For each article, they looked for information about the authors’ financial conflicts of interest. They looked in the article itself, and also in other articles citing the authors that were published in the two years prior to the original article’s date.
Two reviewers blinded to the authors’ financial interests then independently assessed whether each article presented a favourable (ie said rosiglitazone did not increase the risk of heart attack), neutral or unfavourable view about the link between the drug and heart attack risk as well as the recommendations on its use.
The results showed that 45 per cent had financial conflicts of interest and 23 per of these did not disclose this information (in fact three of the studies in the latter category included a statement that declared there were no conflicts of interest).
The researchers also found that nearly all (94 per cent) of the authors who had positive views on the safety of rosiglitazone were more likely to have a financial conflict of interest with a drug company than the authors who were unfavourable toward the drug.
Wang and colleagues concluded that:
“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.”
They pointed out that while the findings do not necessarily show a causal link, they:
“Underscore the need for further progress in reporting in order for the scientific record to be trusted.”
“Association between industry affiliation and position on cardiovascular risk with rosiglitazone: cross sectional systematic review.”
Amy T Wang, Christopher P McCoy, Mohammad Hassan Murad, Victor M Montori.
Published online 18 March 2010
DOI:10.1136/bmj.c1344
Source: BMJ-British Medical Journal, Guardian.
Written by: Catharine Paddock, PhD