Previously, I have focused on the apparent ability of pharmaceutical companies to influence research, the journals that publish this research, and treatment guidelines.
There are many ways that drug companies can do this, including the funding and design of studies. In fact, back in July, I focused on a specific study, funded by the drug company Pfizer, in which the benefits of its statin drug atorvastatin (Lipitor) were somewhat overstated, and the side effects seemingly downplayed. However, this sort of thing is hardly an infrequent occurrence.
Researchers based at the University of California in San Francisco recently reviewed the apparent influence of the drug industry on statin drug research. The review, published online in the journal PLoS Medicine, analyzed 192 studies in which one statin drug was pitted against another [1].
Not surprisingly, drug companies are generally keen to fund studies in which one of their own drugs is compared with one of their rivals. If the results are favorable, this provides major marketing ammunition. However, there are a number of ways in which a drug company can set up a study to help ensure that its product comes out on top.
For instance, there have been claims that drug companies sometimes deliberately choose lower dosages for the comparison drug, making it more likely that their own drug will prove superior. And beyond the actual design of the study, there is also the potential for something known as "publication bias," where trials, which produce unfavorable results, are simply not published.
Of the 192 studies analyzed in the PLoS Medicine review, half had a declared source of funding as a drug company. The results showed that the studies that had funding from a drug company were more likely to report positive results for that company's product—not an itsy bitsy bit more likely to report positive results, but more than 20 times more likely.
And perhaps not surprisingly, the conclusions of these papers generally were more likely to find in favor of the drug whose manufacturer funded the study. Here, the chances of favorable reporting were more than 34 times higher.
One of the authors of the PLoS review, Dr. Lisa Bero, is quoted as commenting that many of the studies assessed in the review "were clearly designed for marketing purposes rather than to rigorously compare the effects of drugs within a class." She also cautions that "patients, policy makers, and physicians should be extremely critical of these head-to-head comparison trials."
An accompanying editorial does not mince its words when it points out that the sponsorship of trials was strongly linked to the results and conclusions of those trials. It also suggests that the evidence base relating to statins may be substantially biased. The more one looks, there seems to be more reason to be highly suspicious of statins and those that promote their use.
References:
1. Bero L, et al. Factors Associated with Findings of Published Trials of Drug–Drug Comparisons: Why Some Statins Appear More Efficacious than Others. PLoS Med 2007 4(6): e184 doi: 10.1371/journal.pmed.0040184
Dr. John Briffa is a London-based doctor, author, and health writer with an interest in nutrition and natural medicine.
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