A major review of medical research has revealed that in nearly one-third of cases, research results were found to be potentially exaggerated, or were totally contradicted by later studies.
The study, published in the Journal of the American Medical Association examined research findings published in three medical journals between 1990 and 2003. The sample included 45 high profile studies of drugs that claimed a particular treatment or drug was effective.
The Associated Press reports that studies found to be unreliable included indications that Vitamin E could prevent heart attacks; that hormone pills provided protection against heart disease in menopausal women, when the reverse was later shown to be the case; and that nitric oxide boosted survival chances in cases of respiratory failure.
In almost all cases, the research that cast doubt on or overturned findings, was a larger, better organised project than the original.
Study author and researcher at the University of Ioannina in Greece, Dr. John Ioannidis, told AP: "Contradicted and potentially exaggerated findings are not uncommon in the most visible and most influential original clinical research."
He added: "There's no proof that the subsequent studies ... were necessarily correct."
However, since none of the treatments later challenged has been adopted as the standard medical recommendation, it is probably a little early to panic. However, as the Editors of the JAMA stress, it is a reminder that one study does not constitute proof that a treatment works.
And as Ioannidis adds: "We all need to start thinking more critically." ®