More medical papers get retracted

I had no idea that so many medical papers get retracted:

The study examined the PubMed database for biomedical research papers retracted from 2000-2010. Almost 5 million publications resulted in 788 retractions over that decade. [Including 88 review articles - how does a review get retracted?]

Actually, I think that it is a good thing that more medical papers are being retracted. Studies indicate that most of them are dubious and cannot be replicated. There are probably millions of papers that ought to be amended, at the least.