Emergency patients with acute abdominal pain feel more confident about medical diagnoses when a doctor has ordered a computed tomography (CT) scan, and nearly three-quarters of patients underestimate the radiation risk posed by this test, reports the Annals of Emergency Medicine.
“Patients with abdominal pain are four times more confident in an exam that includes imaging than in an exam that has no testing,” said the paper’s lead author. “Most of the patients in our study had little understanding of the amount of radiation delivered by one CT scan, never mind several over the course of a lifetime. Many of the patients did not recall earlier CT scans, even though they were listed in electronic medical records.”
Researchers surveyed 1,168 patients with non-traumatic abdominal pain. Confidence in medical evaluations with increasing levels of laboratory testing and imaging was rated on a 100-point scale. Then, to assess cancer risk knowledge, participants rated their agreement with these factual statements: “Approximately two to three abdominal CTs give the same radiation exposure as experienced by Hiroshima survivors,” and “Two to three abdominal CTs over a person’s lifetime can increase cancer risk.”
Median confidence in a medical evaluation without ancillary testing was 20 (95 percent confidence interval [CI], 16 to 25) compared with 90 (95 percent CI, 88 to 91) when laboratory testing and CT were included. About 75 percent of patients underestimated the amount of radiation delivered by a CT scan (assessed by comparing it to chest radiography) and cancer risk comprehension was poor. Median agreement with the Hiroshima statement was 13 (95 percent CI, 10 to 16) and with the increased lifetime cancer risk statement was 45 (95 percent CI, 40 to 45).
Further, only 3 percent of patients understood that CT scans increased a person’s lifetime risk of cancer. Some estimates hold that 1.5 to 2 percent of all cancers in the U.S. may be attributable to the radiation from CT exams.
“Physicians use abdomen-pelvis CT scans because they have been demonstrated to increase certainty of diagnosis, decrease the need for emergency surgery, and avert up to a quarter of hospital admissions,” said the study author. “At the same time, there is growing concern about the long-term consequences of CT scans, particularly in patients who receive many of these scans over the course of their lifetime.”
And, they don’t report that they’ve gotten previous CT scans. Of 365 patients who reported no previous CT, 142 (39 percent) had one documented in their electronic medical record.
There’s plenty of circumstances in healthcare when testing is warranted, or even when unneeded tests can’t be avoided. Consider this scenario involving a patient who transferred to a second hospital, and since the two facilities didn’t use a common electronic medical record, the doctor had to order a duplicate X-ray for the work-up.
But scans aren’t always a benefit. Use of CT scans has grown 16 percent over the years. Archives of Internal Medicine offers an short and excellent read on the subject in its “Less is More” section. The authors wrote, “Often, diagnostic tests are ordered without questioning how the result will or should change patient treatment. Instead, tests are ordered to ‘reassure,’ ‘just to be sure,’ ‘just in case,’ or ‘just to know.’”
And then, one test result requires another, and another, or leads to an invasive test that resulted from a false positive. All this before the physician sees the patient.
“[T]here are safer ways to reassure patients,” the authors wrote. “Physicians are (still) highly respected professionals, and patients value our advice. Talking with our patients should be our first choice for reassurance; tests should be reserved for cases in which the benefits can be reasonably expected to outweigh the risks.”
*This blog post was originally published at ACP Internist*