Patient preferences and acceptable risk for computed tomography in trauma

Abstract

Background: Rising use of computed tomography (CT) to evaluate patients with trauma has increased both patient costs and risk of cancer from ionizing radiation, without demonstrable improvements in outcome. Patient-centred care mandates disclosure of the potential risks, costs and benefits of diagnostic testing whenever possible.

Objective: We sought to determine (1) patient preferences regarding emergency department (ED) real-time discussions of risks and costs of CT during their trauma evaluations; and (2) whether varying levels of odds of detection of life-threatening injury (LTI) were associated with changes in patient preferences for CT.

Methods: Excluding patients already receiving CT and patients with altered mental status, we surveyed adult, English-speaking patients at four Level I verified trauma centres. After informing subjects of cancer risks associated with chest CT, we used hypothetical scenarios with varying LTIs to assess patients' preferences regarding CT.

Results: Of 941 patients enrolled, 50% were male and their mean age was 42 years. Most patients stated they would prefer to discuss CT radiation risks (73.5%, 95% CI [66.1-80.8]) and costs (53.2%, 95% CI [46.1-60.4]) with physicians. As the odds of detecting LTI decreased, preferences for receiving CT decreased accordingly: LTI 25% (desire 91.2%, 95% CI [89.4-93.1]), LTI 10% (desire 79.3%, 95% CI [76.7-81.9]), LTI 5% (desire 69.1%, 95% CI [66.1-72.1]) and LTI <2% (desire 53.8%, 95% CI [50.6-57.0]). If the LTI was <2% and subjects were required to pay $1000 out-of-pocket, only 34.5% (95% CI 31.4-37.5) would opt for CT.

Conclusion: Most non-critically injured patients prefer to discuss radiation risks and costs of CT prior to receiving imaging. As the odds of detecting LTI decrease, fewer patients prefer to have CT; at an LTI threshold of 2%, approximately half of patients would prefer to forego CT. Adding out-of-pocket costs reduced this proportion to one-third of patients.

Keywords: Acceptable risk; Patient preferences; Radiation risk; Trauma CT; Trauma imaging.