Modern medicine has been hugely successful at reducing the impact of disease and increasing life expectancy.
In spite of this, too much medical decision making is based on insufficient evidence. As a result, doctors and other health professionals have sometimes harmed patients instead of helping them.

Avandia was withdrawn after evidence of adverse events mounted up
As recently as 2010, for example, the diabetes drug rosiglitazone (Avandia) was found to have caused serious cardiovascular events such as heart attacks and strokes in spite of being licensed for over 10 years.
How we can prevent these things from happening again is the theme of Testing Treatments interactive (TTi), a family of websites Minervation has produced with an international group of collaborators.
TTi is about how we tell whether one treatment is better than another. In other words, it’s about what constitutes a “fair test” of the effects of treatments.