His research looked at 222 scientific articles about erection pills and pills to delay ejaculation. It shows that it is quite possible that subjects figure out in which test group they are in. This is possible because people in the experimental group experienced side effects. People in a placebo group do not have this clue. Frederik Feys found out that little information about this is published in medical journals. Without this information, the reliability of drug testing can be questioned.
The research has a clear and important message: clinical studies should test whether they happened double blind. If they do not, or they do not report about this, it is possible that we massively swallow pills that work as placebo pills, but come with side effects. Only by testing the double blind, we know for sure whether drugs are effective and safe.
PhD thesis, successfully defended on November 24th, 2015
Department of Family Medicine and Chronic Care, Vrije Universiteit Brussel, Belgium
The Placebo Effect in Sexual Medicine: Methodological Factors in Randomized Clinical Trials
Frederik Feys, MSc, PhD