Why doctors in the United States order so many CT scans and MRI tests

It’s commonly thought that health care in the United States is heavily dependent on diagnostic testing.

But how do we compare with the rest of the world? Perhaps these graphs, courtesy of the New York Times can provide a stark illustration.

Here’s the data regarding CT scans, showing the number of tests per 1,000 people. Guess which country’s on top:

ct scan usage chart

Same story with MRIs:

mri usage chart

Of course, there are plenty of reasons for this, including the widespread practice of defensive medicine, and a fee for service payment system that rewards some doctors (i.e. those who own their own machines, which not all physicians do), among others. In other words, perverse systemic incentives within our health system.

But patients bear some responsibility, as well. There are some who believe that more tests is better medicine, and to that end, an expectation that the “best” health care includes as much testing as possible. It is up to the medical profession to change that mentality, and educate patients about the risks of these tests. CT scans and the growing concern with radiation, for instance.

There is no single magic bullet. All of these variables have to be addressed if there’s any hope to decreasing the number of tests that we perform in the United States.