Today in the New England Journal of Medicine, the most well regarded journal of research and practice for internists, an article appeared that referred to medical harm. I think it may be available to non subscribers at http://content.nejm.org/cg
The number of CAT scans and heart imaging studies that are done is rapidly increasing, and yet there is no evidence these save lives or improve health in most instances. There are definitely times when they are helpful or appropriate, but most of them may be time and money wasted.
But waste is only part of the picture. Most imaging procedures expose people to radiation, and at this point, with the amount of tests people have been getting, about 2% of cancers may be attributable to radiation from CAT scans. The number of CAT scans performed has quadrupled since 1992, and when I look at the graph, there does not seem to be any evidence of this growth slowing. So the extra CAT scans done today will be responsible for an even larger percentage of cancers in future years.
It is hard to track the harm done by radiation exposure because it happens so many years after the actual procedure, which makes it difficult for doctors or patients to put the harm concept together with the test that's done "just to make sure everything's OK." In order to do no harm, we so strongly need good doctor and patient education about the reasons to do and not to do expensive testing, and more universal understanding that what we pay the big bucks for in medical care is not necessarily what makes us healthier.