In 2007, a study in the New England Journal of Medicine found that the radiation from CT scans — the tests regularly used to detect internal injuries or signs of cancer — is likely responsible for 2 percent of cancer cases in the United States.
While lots of Americans undergo CT scans (their use has tripled over the past 15 years), that research is unlikely to come up in doctors' offices: Two-thirds of patients in a new JAMA study reported hearing nothing of the risks of the diagnostic procedure.
Meanwhile, 17 percent felt like they played an active role in a discussion over whether this diagnostic test was the best path forward.
"Our study indicates that most decisions to undergo outpatient CT are made by physicians and risk communication is infrequent," a team of researchers led by University of Colorado's Tanner Caverly writes. "The risk communication that took place had limited impact: respondents who recalled discussing the benefits and risks of imaging did not have better knowledge."
Would a conversation about the potential risks have made a difference? Caverly's team asked a few other questions that suggest it would: Patients undergoing the scan have little idea about the radiation involved. One-quarter self-identified radiation as a risk of a CT scan; 37 percent were able to identify CT scans as having a higher level of radiation than a chest x-ray.
There's a burgeoning movement in medicine right now to cut back on unnecessary treatment or overuse of care. Much of this has been led by a group called Choosing Wisely, which has collaborated with dozens of medical societies to come up with lists of procedures that doctors themselves don't think they ought to be using.
One of their key messages is that more care isn't necessarily better; all medicine comes with some level of risk. That message does not, however, seem to be delivered in the doctor's offices studied here