A quote from John Maynard Keynes used to illustrate a recent Minerva entry in the BMJ.
They reported a recent article in the Mayo Clinic Proceedings, titled “A decade of reversal”. The study took ten years of articles from the New England Journal of Medicine and assessed them to see if they were supporting the reversal of a particular medical practice at the time of publication.
They identified 146 areas of medical practice that were reversed by the publications over the ten years. Almost all areas of medicine were affected. Many of these articles were controlled trials that provided the necessary evidence.