Industry-sponsored studies are likely to produce results that flatter the sponsor’s drug.

So how do we know how effective drugs are? Often we look to medical trials to determine whether certain medicines are worth taking. Unfortunately, however, not all trials are created equally.

Trials that are funded by pharmaceutical companies are more likely to produce results skewed in their favor.

This bias becomes startlingly evident when you look at the results of Harvard and Toronto researchers’ 2010 survey of over five hundred medicinal trials. The survey asked two main questions: Did the results favor the test drug? Were they funded by the industry?

Of the industry-funded studies, 85 percent yielded positive results, compared to only 50 percent of the government-funded trials.

This sort of huge discrepancy indicates that studies sponsored by the pharmaceutical industry produce positive results that cater to industry interests.

In addition, industry-funded trials are often riddled with hidden methodological flaws that make drugs appear better than they are.  

Let’s take a look at the multinational pharmaceutical corporation Pfizer, for example, which published several trials on a drug called Pregabalin designed to treat pain. During these trials, researchers measured participants’ pain at regular intervals.

However, as is often the case in medical trials, some participants exited the study because they were experiencing the drug’s negative side effects.

In these cases, Pfizer decided to take the last measurement of pain severity – while participants were still on the drug – and simply carry that over into the remaining measurements. This technique is deceptive because it disregards the negative side effects.

When the analysis was eventually redone – this time properly – Pfizer’s “last observation” method was unsurprisingly revealed to have overestimated the improvement in pain by about 25 percent.