Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Patient Perceptions of Computed Tomographic Imaging and Their Understanding of Radiation Risk and Exposure – Part I

Also posted over at Paramedicine 101 (now at EMS Blogs) and at Research Blogging. Go check out the excellent material at these sites.

How do we make medical decisions?

Do we have any idea of what we are deciding?

How can we improve our decisions?

This study looks at the knowledge of radiation risk among patients with abdominal pain. Some want a CT (Computed Tomographic Imaging), while others may not feel they are better at diagnosis than the doctor. What do they know about the radiation exposure from a CT?

CT is not inherently bad –

Unlike ultrasonography or radiography, CT provides greater level of detail and allows simultaneous imaging of organs, vessels, musculature, and bone.   . . .   Additional support for the liberal use of abdomen-pelvis CT is that it has been demonstrated to increase emergency physician certainty of diagnosis, decrease the need for emergency surgery from 13% to 5%, and avert up to 24% of proposed hospital admissions.6,7 [1]

On the other hand . . .

there is growing concern that CT is being overused, and it is estimated that 1.5% to 2.0% of all cancers in the United States may now be attributable to the radiation from CT examinations.2,4 [1]

About 1.6 million new cases of cancer are expected this year.[2]

If correct, that would mean 24,000 to 32,000 new cases of cancer from CT.

About 572 thousand – or almost 0.6 million people are expected to die from cancer this year.[2]

The new cancers are about 3 times the rate of the deaths. That means that a lot more people are being cured/going into remission, than are dying. (As a side issue – the cures are not due to alternative medicine. However, some of the deaths are due to delays in receiving treatment with real medicine, because of someone’s faith in alternative medicine. If anyone knows of any good research that suggests otherwise, please provide it. Cancer patients would love to have more choices of treatments that really work.)

Even with so much improvement in the treatment of cancer, are we significantly increasing our risk of cancer with little benefit, or no benefit?

We performed a cross-sectional study of adult patients aged 18 years and older who presented to the emergency department (ED) for the evaluation of acute, nontraumatic abdominal pain and assessed their expectations and confidence with increasing diagnostic levels of medical evaluation and their understanding of radiation risk and exposure from abdomen-pelvis CT.[1]

Part 1 is –

The goals of this investigation were 3-fold. The first was to assess patients’ confidence levels with medical evaluations that ranged from a physician-conducted history and physical examination (minimal technology) to one that included a history and physical examination, blood work, and an abdomen-pelvis CT (maximum technology).[1]

What do patients with abdominal pain want?

Maybe even more than pain medicine, patients seem to want a CT. If that doesn’t provide answers, they want another one. As if radiation will work differently or the body will change or . . . .

Click on the image to make it larger.

Patient confidence in the accuracy of progressive levels of medical evaluation is presented in Table 2. Confidence was lowest for a medical evaluation that was limited to a physician-conducted history and physical examination. The addition of laboratory testing and imaging resulted in a nearly 4-fold increase in confidence, with the highest confidence level in patients who were presented with the option of CT.[1]

Would physicians be much better at answering the same questions?

To be continued tomorrow in Part II, Sunday in Part III, and maybe Monday in Part IV.


[1] Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure.
Baumann BM, Chen EH, Mills AM, Glaspey L, Thompson NM, Jones MK, Farner MC.
Ann Emerg Med. 2011 Jul;58(1):1-7.e2. Epub 2010 Dec 13.
PMID: 21146900 [PubMed – indexed for MEDLINE]

Free Full Text from Annals of Emergency Medicine with links to Free Full Text PDF Download

[2] Cancer Facts & Figures 2011
American Cancer Society
Page with link to various forms of information – a Slide Presentation, and Full Text PDF Download

Baumann BM, Chen EH, Mills AM, Glaspey L, Thompson NM, Jones MK, & Farner MC (2011). Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure. Annals of emergency medicine, 58 (1), 1-700 PMID: 21146900


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