How much of orthodox medicine is evidence based?

Scientific heavyweights deplore the NHS money wasted on unproved and disproved treatments used by practitioners of complementary and alternative medicine (CAM),1 2 but Lewith, a CAM proponent [see previous letter], is cited elsewhere as saying that the BMJ reckons that 50% of the treatments used in general practice aren't proved, and 5% are pretty harmful but still being used.3

His data were taken from the BMJ Clinical Evidence website (http://clinicalevidence.com/ceweb/about/knowledge/jsp, viewed 6 May 2007). A pie chart indicates that, of about 2500 treatments supported by good evidence, only 15% of treatments were rated as beneficial, 22% as likely to be beneficial, 7% part …