If your doctor advises you to have an X-ray, a CT scan, or an MRI, do you immediately agree, or do you question whether or not you actually need the test? It might be in your best interests to ask a few questions, according to a study which found that a doctor's prior requests for tests as well as who owned the imaging equipment were strong indicators of whether a test was actually necessary.  

"Whether or not you get unnecessary imaging is partly explained by how much unnecessary imaging the clinician orders in general and whether or not the clinician owns the imaging equipment," said lead author Dr. Arthur Hong, Assistant Professor of Internal Medicine and Clinical Sciences at UT Southwestern Medical Center.

"For patients who got an MRI but did not need one, which doctor they went to mattered more than the injury or symptom that they had. With people more on the hook for the costs of their care, it's increasingly important for physicians to offer financially responsible care," Hong said.

Uncomplicated back pain and uncomplicated headaches are two of the most common reasons patients with health insurance received unnecessary imaging such as X-rays, computed tomography (CT), or magnetic resonance imaging (MRI). Previous studies have found that this type of unnecessary care may account for up to one-third of all medical expenditures.

In addition, low-value services can trigger downstream cascades of unnecessary care and clinical harm, said Hong.

The study examined the records of 100,977 primary care physicians, specialist physicians, and chiropractors. They found that chiropractors and specialists ordered the most testing for frequent back pain, and primary care physicians ordered the tests for headaches.  

The study was published in JAMA Internal Medicine.

Several studies have pointed to the radiation dangers caused by some types of imaging tests, especially CT scans. A study conducted by Columbia University concluded that up to 2 percent of all cancers are caused by CT scans. Unfortunately, doctors may be oblivious to the danger. A study from Yale University found that only 9 percent of emergency room doctors were aware of the cancer risk posed by radiation produced by medical tests.  

Other studies show that as many as a third of CT scans are unnecessary.