Elsevier

Injury

Volume 45, Issue 9, September 2014, Pages 1345-1349
Injury

Patient preferences and acceptable risk for computed tomography in trauma

https://doi.org/10.1016/j.injury.2014.03.011Get rights and content

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
tm) 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.

Introduction

The use of computed tomography (CT) in United States health care has increased significantly over the past few decades, from approximately 2 million scans performed in 1980 to 85.3 million in 2011 [1], [2], [3]. Similarly, emergency department (ED) advanced diagnostic imaging for injury (primarily CT) has increased from 6% of visits in 1998 to 15% in 2007, without corresponding increases in hospital admissions or diagnoses of life-threatening conditions [4]. This increased CT use exposes more patients to potentially harmful ionizing radiation, contributes to ED crowding, and generates annual radiographic charges approaching $100 billion [5].

Diagnostic medical imaging is a major source of non-natural radiation exposure, accounting for 15•20% of annual doses [6]. In the evaluation of patients with trauma, CT is the largest source of radiation [6]. When compared to plain chest radiographs, for example, CT scans involve as much as 119 times more radiation [1]. This ionizing radiation has been associated with an increased cancer risk in a linear, dose-dependent relationship [6], [7]. It is estimated that 1 in 270 women who undergo CT coronary angiography at age 40 will develop cancer as a direct result of the scan, and approximately 29,000 future cancers may be related to the CTs performed in the U.S. during 2007 alone [1], [7], [8]. Although public awareness of radiation risk is increasing, most patients still remain unaware of radiation exposure risk from CT [2], [9].

Respect for patient autonomy mandates providing informed consent for procedures that carry risk whenever possible. Yet, despite emerging knowledge about the potential cancer risks of CT, trauma imaging is typically obtained without informing patients of its risks or discussing their preferences. Patients may prefer to forego CT and accept a chance of missed injury in order to avoid the radiation exposure and costs of CT. Our objectives of this study were to determine (1) patient preferences for the discussion of risks and costs of CT during trauma evaluations in the ED, and (2) whether varying odds of detecting life-threatening injury (LTI) by CT changes these preferences. Knowledge of these patient preferences and risk tolerances may be useful to promote patient autonomy and shared decision making.

Section snippets

Study design, participants, and setting

We conducted this cross-sectional survey of ED patients who presented to four urban American College of Surgeons verified Level I trauma centres between July 2012 and April 2013. After providing a scripted consent that emphasised voluntary and anonymous participation, we surveyed a convenience sample of patients with the following exclusions: (1) receiving CT scan, (2) altered mental status, (3) intoxication, (4) critical illness, (5) incarceration, (6) psychiatric hold, and (7) inability to

Results

Of the 941 subjects enrolled, the mean age was 42 years and 50% were male. See Table 1 for complete subject characteristics.

Most subjects stated that they would prefer to discuss trauma CT radiation risks (73.5%, 95% CI [66.1, 80.8]) and costs (53.2%, 95% CI [46.1, 60.4]) with their physicians prior to receiving CT. As the hypothetical odds of LTI decreased, the desire for CT scan decreased accordingly: LTI 25% (desire 91.2%, 95% CI [89.4, 93.1]), LTI 10% (desire 79.3%, 95% CI [76.7, 81.9]),

Discussion

Similar to the recent work of Youssef et al., we found that nearly three quarters of non-critically ill patients want to discuss radiation risks before receiving CT (when possible) [17]. Considering that we asked these preference for discussion questions before presenting the statement about radiation risk, patients may already have been aware of some of these radiation concerns. Our study is novel in exploring variable acceptable risk thresholds and the effects of costs on preference for

Conclusions

Most non-critically injured ED patients prefer to discuss radiation risks and costs of CT prior to receiving imaging for trauma. As the odds of detecting LTI decrease, fewer patients prefer to have CT, and at an LTI threshold risk of <2%, approximately half of patients would prefer to forego imaging. Only one-third of patients desired CT imaging when out-of-pocket costs of $1000 were coupled with LTI risk <2%. Clarification of patient preferences may establish a new paradigm in advanced trauma

Author contributions

All authors contributed to the study design and implementation. All authors collected data, participated in ongoing site monitoring and provided supervision for the study. RMR, CLA, TH, and AR performed the data analysis. All authors contributed to interpretation of the analyses. RMR, TH and AR wrote the initial manuscript draft and all authors reviewed and contributed to its revision.

Conflict of interest statement

The authors have no conflicts of interest to declare regarding this research.

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