In previous posts, such as here and here, I have focused on the apparent ability of pharmaceutical companies 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 occasional occurrence.
Researchers based at the University of California, in San Francisco, USA, recently reviewed the apparent influence of the drug industry in the area of research in statin drugs. The review, published on-line in the journal PLoS medicine, analysed 192 studies in which one statin drug was pitted against another . Not surprisingly, drug companies are generally keen to fund studies in which one of their owns drugs is compared with one of their rivals. If the results are favourable, 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 it’s 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 unfavourable results are not simply published.
Of the 192 studies analysed in the PLoS Medicine review, half had a declared source of funding as a drug company which made one of the drugs being tested. The results showed that the studies which had funding from a drug company were more likely to report positive results for its product being tested. But not a itsy bitsy bit more likely, but more than TWENTY TIMES more likely. And perhaps not surprisingly, the conclusions of these papers generally were more likely to find in favour of the drug whose manufacturer funded the study. Here, the chances of favourable reporting were more than THIRTY-FOUR 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, the more reason there seems to be to be highly suspicious of statins and those that promote their use.
2. 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