Excerpt from Bad Pharma: How Drug Companies Mislead Doctors and Harm Patients, by Ben Goldacre. Published by Faber and Faber, Inc. © 2013 Ben Goldacre. Excerpted with permission from the publisher. All Rights Reserved.
Before we get going, we need to establish one thing beyond any doubt: industry-funded trials are more likely to produce a positive, flattering result than independently funded trials. This is our core premise, and you’re about to read a very short chapter, because this is one of the most well-documented phenomena in the growing field of “research about research”. It has also become much easier to study in recent years, because the rules on declaring industry funding have become a little clearer.
We can begin with some recent work: in 2010, three researchers from Harvard and Toronto found all the trials looking at five major classes of drug—antidepressants, ulcer drugs and so on—then measured two key features: were they positive, and were they funded by industry? They found over five hundred trials in total: 85 per cent of the industry-funded studies were positive, but only 50 per cent of the government funded trials were. That’s a very significant difference.
In 2007, researchers looked at every published trial that set out to explore the benefit of a statin. These are cholesterol lowering drugs which reduce your risk of having a heart attack, they are prescribed in very large quantities, and they will loom large in this book. This study found 192 trials in total, either comparing one statin against another, or comparing a statin against a different kind of treatment. Once the researchers controlled for other factors (we’ll delve into what this means later), they found that industry-funded trials were twenty times more likely to give results favoring the test drug. Again, that’s a very big difference.
We’ll do one more. In 2006, researchers looked into every trial of psychiatric drugs in four academic journals over a ten-year period, finding 542 trial outcomes in total. Industry sponsors got favorable outcomes for their own drug 78 per cent of the time, while independently funded trials only gave a positive result in 48 per cent of cases. If you were a competing drug put up against the sponsor’s drug in a trial, you were in for a pretty rough ride: you would only win a measly 28 per cent of the time.
These are dismal, frightening results, but they come from individual studies. When there has been lots of research in a field, it’s always possible that someone—like me, for example—could cherry-pick the results, and give a partial view. I could, in essence, be doing exactly what I accuse the pharmaceutical industry of doing, and only telling you about the studies that support my case, while hiding the reassuring ones from you.
To guard against this risk, researchers invented the systematic review. We’ll explore this in more detail soon, since it’s at the core of modern medicine, but in essence a systematic review is simple: instead of just mooching through the research literature, consciously or unconsciously picking out papers here and there that support your pre-existing beliefs, you take a scientific, systematic approach to the very process of looking for scientific evidence, ensuring that your evidence is as complete and representative as possible of all the research that has ever been done.
Systematic reviews are very, very onerous. In 2003, by coincidence, two were published, both looking specifically at the question we’re interested in. They took all the studies ever published that looked at whether industry funding is associated with pro-industry results. Each took a slightly different approach to finding research papers, and both found that industry-funded trials were, overall, about four times more likely to report positive results. A further review in 2007 looked at the new studies that had been published in the four years after these two earlier reviews: it found twenty more pieces of work, and all but two showed that industry sponsored trials were more likely to report flattering results.