One of the constants in any talk about the cost of U.S. health care is the heated discussion about defensive medicine. That occurs when physicians order excessive tests, such as CT scans, to protect themselves against possible lawsuits rather than as a useful adjunct in diagnosing or treating an injury or an ailment. The debate turns on two salient points. The first is the cost the tests impose on the system. The second, often overlooked, is the cumulative risk faced by patients who undergo repeated scans over the course of their lifetime.
The former is relatively simple to calculate. Millions of such tests are performed annually, Multiply that number by the cost of each test — which varies considerably — for a dollar amount. Some medical economists put the total at hundreds of millions or even billions of dollars. Whatever the number, it is inordinately expensive.
The latter has been more difficult to quantify. That’s no longer the case. Recent studies offer a sobering assessment of the risks the tests can pose. The possible perils are significant. The Associated Press recently reported that U.S. patients receive the most medical radiation — which can increase the risk of cancer — in the world. Indeed, the average American’s exposure has increased by a factor of six in recent decades.
One result, researchers report, is that as many as 20 million adults and 1 million children in the United States now face possible harm because of radiation exposure. The study estimates that up to 2 percent of cancers in the United States at some point in the future could be linked to radiation from CT scans being ordered now. Given that, it is imperative that current standards and guidelines for diagnostic and therapeutic medical radiation be revised to protect the public.
There is movement in that direction. The Food and Drug Administration wants to impose new rules that would require standard dosages for specific tests and to set up a system that would allow patients to keep track of doses. Those rules should be implemented.
Some CT scans, experts say, can deliver 50 to 100 times more radiation than a conventional X-ray. Actual dosage does depend on the part of the body being examined and the machine used, but dangerous levels of exposure can mount up quickly. One physician, for example, reported that he has seen individuals “who are 30 years old who had at least 18 scans done. That is a big problem,” he said.
Increased FDA oversight, public education about the dangers of excessive radiation and reminders that ultrasound or magnetic resonance imaging (MRI) can be a safer but still effective procedure should improve public health in the long term. The best protection against possible harm, though, resides with the patient. He or she should ask if a CT scan or similar high-radiation test is necessary every time a physician orders one for them.