Check the 'small print'

"A medical research study funded by a drug or device company is four times more likely to have results that turn out to be favourable to the company's product than independent studies funded from other sources are.
And since up to three-quarters of the clinical trials published in major medical journals are funded by industry, that means a lot of very favourable results that have been essentially bought and paid for by the very companies that stand to gain financially by positive reports in medical journals."

Reprinted with permission.
http://ethicalnag.org/2012/09/30/clinical-trials-drug-companies-results/