By Steven Weinberger

A colleague recently told me about his expensive encounter with the health-care system. He had an episode of lower-back pain similar to others he had experienced intermittently for 20 years, but this time he decided to see a doctor about it. An MRI scan, required before he was even seen, was read as possibly showing a mass in his liver. This unexpected and worrying finding led to an ultrasound that was not helpful in diagnosing the problem; another MRI that turned out to be of poor quality; yet another MRI that ruled out a liver mass but showed "something on the kidney"; and finally a CT scan that found neither liver nor kidney abnormalities.

In the end, my colleague's back pain improved after some physical therapy. But the health-care system was left with a bill for three MRI scans, an ultrasound, and a CT scan - all of which were unnecessary, and none of which improved my colleague's health. His health insurance provider ultimately paid approximately $3,600 on a bill of more than $6,200.

Such diagnostic testing run amok is unfortunately all too common, and it's an important component of the escalating health-care costs that are contributing to the nation's financial woes. I have spoken with fellow physicians around the country about this issue, and they have recounted many similar stories of overuse and misuse of testing.

I can speak from personal experience, too. I recently had a minor orthopedic procedure performed on one of my knees, but not before I received a battery of preoperative lab tests, a chest X-ray, and an electrocardiogram - none of which was necessary in my case. The expense for me and my insurance provider was not huge. Multiply it by the number of unnecessary preoperative tests performed around the country every year, though, and now we're talking real money.

Although it's difficult to quantify the impact of excessive testing, some estimates suggest that it costs $200 billion to $250 billion a year, or about 10 percent of U.S. health-care expenditures. Since 2000, the volume of imaging studies and other tests per Medicare beneficiary has risen by about 85 percent - a truly startling indication of the growth in diagnostic testing, much of which is unnecessary and avoidable.

Many factors contribute to the overuse and misuse of testing. They include patient expectations, a lack of guidelines on testing for many clinical problems, a lack of physician awareness about the guidelines that do exist, fear of malpractice litigation, and doctor habits that are hard to break.

The challenge is to identify common types of overuse and misuse, develop guidance on testing where it doesn't exist, and educate doctors and patients about areas where we are raising costs without improving care.

One such area is diagnostic imaging for lower-back pain. The American College of Physicians found strong evidence that X-rays, CT scans, and MRIs don't usually lead to improvements in the health of patients with lower-back pain. Because such patients tend to get substantially better in a few days with exercise and medication, the college recommends that imaging studies be reserved for those who have serious symptoms or are candidates for invasive interventions.

It's important to stress that reducing diagnostic testing where it does not improve patient health does not amount to rationing care. Rationing means withholding care that is likely to improve patients' health. In contrast, avoiding overuse or misuse of diagnostic testing is rational and appropriate, because it eliminates care that increases costs but doesn't improve health.

Besides controlling and even decreasing health-care costs, eliminating such overuse and misuse also protects patients from unnecessary testing risks, such as potential complications, excessive radiation, needless anxiety, and - as in the case of my colleague - another set of unnecessary diagnostic tests.

Current legislative efforts to control health-care costs do not actually control the cost of care; rather, they control health-care payments. Reducing health-care payments without controlling health-care costs raises the specter of rationing, as payments for unnecessary care limit the dollars available for care that's truly needed.

The challenge for health-care providers is to seize opportunities to simultaneously control costs and improve care. Reducing the overuse and misuse of diagnostic testing is just such an opportunity for physicians and patients to work together to improve the health of Americans and of the American economy.