Drug trials submitted to the Food and Drug Administration may differ from the versions that are published, suggesting that healthcare professionals may be reading biased data, new research has found.
Findings published in the journal PLoS Medicine reveal that discrepancies between FDA-submitted results and published results were discovered among several trials analyzed by researchers at the University of California-San Francisco.
The differences included the addition or omission of outcomes, adjustments in statistical significance of outcomes and amendments to the overall conclusion of drug trials.
Medical journals and literature tended to feature more favorable presentations of these medications, the researchers concluded.
"The information that is readily available in the scientific literature to health care professionals is incomplete and potentially biased," the study authors wrote.
To reach their conclusions, the team analyzed 164 trials relating to 33 new drug applications. A total of nine were found to differ, in favor of the drug in question.
The FDA requires that pharmaceutical companies submit a new drug application before they can begin selling a medication.