Informing Patients About Risks and Benefits of Radiology Examinations: A Review Article

Informing Patients About Risks and Benefits of Radiology Examinations: A Review Article Jeremy S. Cardinal, MDa, Richard B. Gunderman, MD, PhDa, Robert D. Tarver, MDa

Communicating the risks, benefits, and alternatives to a planned medical intervention is integral to high-quality patient care. When effective, such communication promotes patient autonomy, alleviates unfounded patient apprehension, and mitigates medicolegal liability. The topic of medical radiation adds to the usual challenges of effective medical communication some special challenges of its own. Among these is a lack of understanding by the general population and health professionals of the benefits and risks of medical radiation, which is compounded by unfamiliar terminology and units of measure. This is further complicated by the fact that many patients have poor comprehension of risk data in general. In this article, the authors present a case, review the ethical basis and legal history of informed consent, and explore the current initiatives, available resources, and further opportunities related to this challenging topic. Key Words: Informed consent, medical radiation, radiology, communication, risk J Am Coll Radiol 2011;8:402-408. © 2011 Published by Elsevier Inc. on behalf of American College of Radiology

A CASE

A 39-year-old woman, pregnant at 34 weeks’ gestation, presented to the emergency department with sudden-onset, 10/10 chest pain that she described as pounding and radiating to the middle of her back. Her chest radiograph suggested a mildly widened mediastinum. The referring obstetrician was concerned for aortic dissection and sought radiologic advice on how best to approach this diagnosis in pregnancy. The radiologist recommended chest CT with intravenous contrast as the most appropriate imaging study. When the obstetrician raised concerns about the radiation exposure to a fetus at 34 weeks’ gestation, the radiologist responded that the risks posed by ionizing radiation and intravenous contrast material were vastly outweighed by the benefits of quickly and accurately diagnosing this acutely life-threatening condition. Satisfied with this explanation, the obstetrician decided to proceed with the CT scan. The next order of business was to discuss the recommendation with the patient. Entering the patient’s room, the radiologist found a thin, anxious-appearing, pregnant woman sitting in a wheelchair. The radiologist introduced himself and began explaining the situation, including the risks, benefits,

a

Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana. Corresponding author and reprints: Richard B. Gunderman, MD, PhD, Indiana University School of Medicine, Department of Radiology, 702 Barnhill Drive, Room 1053, Indianapolis, IN 46202-5200; e-mail: [email protected].

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and alternatives to the proposed CT examination. The patient responded by leaning forward nervously and asking, “What will happen to my baby?” He explained that the most important risk was likely a small increase in the probability of developing childhood cancer, which was dwarfed by the danger of failing to get a rapid and accurate diagnosis of her condition. He quoted estimates for the baseline risk and estimated increase in risk from the CT scan. In addition, he told her that the risk posed to her child from the intravenous contrast material was not known but thought to be minimal. Despite his best efforts, he sensed that the patient did not understand much of what he was saying, other than the fact that her child might get cancer, and that she needed the test anyway. She indicated that she trusted her physicians to act in the best interests of her and her child and that she was ready to proceed with the test. Although informed consent was successfully obtained and the patient willingly signed the consent form, the radiologist emerged from the encounter feeling unsatisfied with the quality of their communication. He suspected that he had engendered an excessive level of concern over radiation risks and had failed to communicate how small they were in comparison with the urgency of diagnosing an aortic dissection. The CT scan was performed immediately, and the images revealed a large, Stanford type A dissection. The fetus was delivered by caesarean section, without complication. Thereafter, the patient underwent successful surgical repair of her aorta. © 2011 Published by Elsevier Inc. on behalf of American College of Radiology 0091-2182/11/$36.00 ● DOI 10.1016/j.jacr.2010.09.007

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The outcome was good: an example of modern medicine saving lives. Yet questions remain: Why was the communication between the radiologist and the patient poor? Is there evidence to suggest more effective methods of communication? Was it necessary to inform the patient of the risks associated with her CT scan, considering the clear indication, emergent nature, and disproportionate benefits? How do these concepts apply in the broader setting of radiology? What do patients understand about radiation and the risks it poses? How do the abstract nature of radiation and the usually limited radiologistpatient relationship affect this communication? What are the expectations of patients, the public, and the legal system for disclosure of risks related to radiologic procedures? What resources are available to radiologists, and how have others addressed this challenge? INFORMED CONSENT

The questions raised relate to informed consent, an ethical and medicolegal concept that has evolved significantly in the past half century, now occupying a central position in modern medicine. An understanding of its history is fundamental when considering how it applies in the presented case and in the broader setting of radiology. It is common among those with limited understanding of informed consent to regard it as a liability waiver. The American Medical Association defines informed consent as “a process of communication between a patient and physician that results in the patient’s authorization or agreement to undergo a specific medical intervention” [1]. Furthermore, the Physician Resources section of the American Medical Association’s Web site lists the following key elements in the informed consent process that a physician should discuss with a patient: ● ● ● ●

● ●

the patient’s diagnosis, if known the nature and purpose of a proposed treatment or procedure the risks and benefits of a proposed treatment or procedure alternatives (regardless of their cost or the extent to which the treatment options are covered by health insurance) the risks and benefits of the alternative treatment or procedure the risks and benefits of not receiving or undergoing a treatment or procedure

The ethical underpinnings of informed consent lie in the bioethical principles of beneficence and autonomy. Berg et al [2] suggest that over the course of the 20th century, the primary justification for informed consent has shifted from the former to the latter. During the age of paternalistic medicine, evidence that patients’ outcomes improved when they shared in knowledge and decision making regarding their condition and treatment

served as justification for informed consent. Hence, involving patients in decision making was regarded as an application of beneficence. The shortcoming of this justification, when viewed through the lens of modern bioethics, is that the justification stands only so long as the patient makes decisions that are consistent with the physician’s view of the patient’s best interests. It tends to dismiss perspectives different from those held by the physician. In recent decades, developments in medical technology, changing political climates, a series of human subject abuses, and the dawning of the information age all contributed to an elevation of the principle of autonomy. We now pay less attention to the benefits of informed consent and focus instead on the fact that failure to inform patients and to involve them in decision making would violate their right to self-determination. As such, the ethical justification for informed consent is now usually formulated in terms of patient autonomy. In the first half of the 20th century, courts defined a patient’s right to self-determination by invoking the tort of battery, which protects an individual from unwanted touching. In the 1914 case Schloendorff v The Society of New York Hospital [3], Justice Cardozo wrote, Every human being of adult years and sound mind has a right to determine what shall be done with his own body; and the surgeon who performs an operation without his patient’s consent commits an assault for which he is liable for damages. This is true except in cases of emergency, where the patient is unconscious and where it is necessary to operate before consent can be obtained.

The case involved a patient who sued after her physician removed a fibroid tumor. She had consented to an abdominal examination under general anesthesia but specifically requested that no operation be performed. The tort of battery remains relevant in disputes over informed consent. It applies to cases in which no consent is obtained, consent is obtained but not for the performed intervention or not for the body part involved, the scope of consent is exceeded, or consent is obtained but not for the physician who performed the procedure. A separate class of legal actions emerged in the mid20th century that were initially prosecuted under the legal theory of battery, but over time, the legal system migrated to addressing them as medical negligence. These involved disputes in which consent was obtained, but with inadequate disclosure of material risks. The distinction between battery and medical negligence has important implications. Medical negligence requires a higher standard of proof, usually requiring expert testimony to establish standard of care. Additionally, damages from battery cases may not be covered by malpractice insurance. In general, to establish medical negligence, the plaintiff must establish 4 elements: duty owed, duty breached, injury, and proximate cause. In informed consent cases, this specifically means the plaintiff must demonstrate

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that (1) the physician had a duty to disclose specific information regarding an intervention received by the patient, (2) the physician failed to disclose this information, (3) the patient suffered an injury, and (4) the injury was the direct result of the intervention, and the patient would have refused the intervention had the physician disclosed the information. The term informed consent first appeared in 1957, in Salgo v Leland Stanford etc Bd Trustees [4], a landmark case involving inadequate consent for a radiologic study. Mr Salgo, the plaintiff, had been referred to Dr Gerbode, a professor of surgery at Stanford Medical School, for treatment of peripheral arterial disease. On the basis of his physical examination findings, Dr Gerbode diagnosed probable occlusion of the abdominal aorta. He admitted the patient to the hospital for further workup and treatment. He ordered an aortogram, which was obtained by a member of the surgical house staff, an anesthesiologist, and two radiologists. The study was uneventful, demonstrating infrarenal occlusion of the abdominal aorta. However, when the patient woke the next morning, he had developed paralysis of both lower extremities. Mr Salgo alleged that he had not been warned of this risk, which Dr Gerbode did not dispute. In his decision, Justice Bray asserted, A physician violates his duty to his patient and subjects himself to liability if he withholds any facts which are necessary to form the basis of an intelligent consent by the patient to the proposed treatment. Likewise the physician may not minimize the known dangers of a procedure or operation in order to induce his patient’s consent.

The justice continued, mitigating this somewhat, At the same time, the physician must place the welfare of his patient above all else and this very fact places him in a position in which he sometimes must choose between two alternative courses of action. One is to explain to the patient every risk attendant upon any surgical procedure or operation, no matter how remote; this may well result in alarming a patient who is already unduly apprehensive and who may as a result refuse to undertake surgery in which there is in fact minimal risk; it may also result in actually increasing the risks by reason of the physiological results of the apprehension itself. The other is to recognize that each patient presents a separate problem, that the patient’s mental and emotional condition is important and in certain cases may be crucial, and that in discussing the element of risk a certain amount of discretion must be employed consistent with the full disclosure of facts necessary to an informed consent.

Bray’s framing of the issue addresses the tension between the ethical principles of autonomy and beneficence but offers little guidance regarding how to balance the two. It also reflects the historically more prominent position of beneficence in the statement “the physician must place the welfare of his patient above all else.” In contemporary bioethics, the balance inclines more toward patient autonomy. Of note, the language regarding informed consent from Justice Bray’s decision was taken verbatim from an amicus curiae brief submitted by the lawyers for the American College of Surgeons to the

California Court of Appeals [5]. In other words, the original legal description of informed consent was written by lawyers representing physicians. In 1960, in another landmark case, Natanson v Kline [6], the Kansas Supreme Court established the professional practice standard of disclosure, setting the standard for what a physician should disclose as what a reasonable physician would reveal under similar circumstances. Additionally, the ruling was the first to ground physician informed consent liability in the legal theory of negligence rather than battery [7]. In this case, Mrs Natanson sued Dr Kline after receiving severe radiation burns from cobalt radiation therapy, claiming that he never discussed this risk with her. The decision stated that expert testimony from a medical witness is required to establish whether the disclosure in question accords with what a reasonable medical practitioner would make under similar circumstances. This carried forward the precedent for proving breach of duty from malpractice law on the basis of the theory of negligence. In 1972, a ruling in Canterbury v Spence [8] rejected the professional practice standard and posited in its place a prudent patient standard of disclosure. In the case, Mr Canterbury was partially paralyzed after a laminectomy for severe back pain, having not been warned of a 1% risk for this complication. The court declared that [a] risk is thus material when a reasonable person, in what the physician knows or should know to be the patient’s position, would be likely to attach significance to the risk or cluster of risks in deciding whether or not to forego the proposed therapy.

According to this prudent patient standard, expert witness testimony is no longer required. The standard is defined by what a jury determines a reasonable person in a position similar to the plaintiff would need to know. Many states have adopted the prudent patient standard, but others still apply the professional practice standard. The legal application of informed consent was again extended in a 1980 case, Truman v Thomas [9]. In this case, the children of a woman deceased from cervical cancer successfully sued her physician for failing to inform her of the risks of not having a Pap test, which she had refused on multiple occasions, thus extending the concept of informed consent to include informed refusal. Of note, the tort of battery, the original legal theory applied to consent cases, has no relevance in this case. Noted radiologist and legal expert Leonard Berlin [10] reviewed a 1997 case involving a patient who underwent myelography after a diagnosis of nonspecific peripheral neuropathy. A general radiologist interpreted the findings of the study as normal. Six months later, after continued neurologic deterioration, the patient presented to another facility, where a neuroradiologist reinterpreted the original myelogram as showing an arteriovenous malformation of the spinal cord. The diagnosis was con-

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firmed by angiography, but the patient had suffered irreversible damage. A neuroradiology expert retained by the plaintiff testified that during the informed consent process, the general radiologist should have disclosed that, as a general radiologist, he possessed limited knowledge of neuroradiology. Although the portion of the lawsuit involving the radiologist was eventually dropped, this case serves as an example of a potential requirement that the informed consent process include the disclosure of provider-specific information, a requirement that has been upheld in some circumstances [11]. The legal application of the concept of informed consent continues to expand. THE CHALLENGES

Simply informing patients does not guarantee success. Do patients in fact understand the information being provided to them and retain such information over time? Studies have demonstrated poor comprehension of risk data by patients. Sheridan et al [12] evaluated the ability of patients in the setting of a university internal medicine clinic to use various statistical quantities (relative risk reduction, absolute risk reduction, and number needed to treat) in two settings: choosing which of two proposed treatments was more effective and calculating the benefit. The patients identified the treatment that provided greater benefit only 44% of the time and were able accurately to calculate the benefit of treatment only 13% of the time. The study also attempted to assess each participant’s numeracy by posing 3 questions related to basic probability. For example, if the chance of winning a lottery prize is 1%, how many people out of 1,000 will likely win? The investigators found that although 70% of participants considered themselves good with numbers, only 2% answered all 3 questions correctly, and 41% failed to answer any questions correctly. Herz et al [13] evaluated the retention of informed consent information by 106 patients before anterior cervical fusion or lumbar laminectomy. Each patient underwent a multistep process of informed consent, including a consultation with a neurosurgeon to discuss the diagnosis, proposed intervention, alternatives, risks, and benefits, and later a separate patient education conference performed by a master’s-level nurse educator covering the same topics. Testing immediately after the patient education conference demonstrated a 43.5% performance rate on all topics. Only 22.8% could list the risks associated with the procedure. The situation is further complicated in the setting of radiology by the abstract nature of radiation, the prolonged latency of the stochastic risks it poses, and the unfamiliarity of most members of the general public and many health professionals with the terminology and units of measure related to radiation. A patient preparing to undergo laminectomy may not understand the finer points of the procedure but likely has an intuitive sense of

what it means to have the flesh cut, and the risk for spinal cord injury is concrete. In contrast, radiation is invisible and unfamiliar to patients, as are the mechanisms by which it damages tissue and the long-term harms that may result. Few patients are likely to understand the concept of natural background radiation and the fact that the radiation exposure from common radiologic procedures often falls within the range of noise. A patient will likely grasp “I am going to make a 3-inch incision” far better than “You will receive 3 millisieverts of radiation.” Should patients attempt to pursue independent learning on the topic of radiation, they would likely encounter terms such as absorbed dose, effective dose, equivalent dose, and entrance skin dose and units of measure including the becquerel, curie, roentgen, gray, rad, sievert, and rem. The often limited patient-physician relationship in radiology poses another set of obstacles. Although explaining the benefits of a procedure is a key component of the informed consent conversation, a radiologist may not know how the study results will influence a clinician’s care plan for a patient, particularly for high-volume, lowexposure examinations such as plain radiography. Also, the radiologist likely lacks an established relationship with the patient. Another challenge confronting any attempt at formulating a general approach to informed consent is the highly variable clinical environment in which it takes place. Key factors include the urgency of the proposed intervention and its risks, as well as patient factors, including level of education, emotional state, effects of illness, and variable preferences for information. Variations in each of these parameters warrant a flexible approach. The process is likely to look much different for an asymptomatic outpatient undergoing an elective procedure than for a patient with an acute, life-threatening illness in severe pain and emotional distress. Similarly, risks and their relevance will vary among patients. A risk for inducing cancer 20 years later should mean something quite different to an 80-year-old, terminally ill patient and a healthy 18-year-old. WHY COMMUNICATION MATTERS

Communication of the risks associated with medical radiation promotes patient autonomy. Although the risk to any individual patient from diagnostic radiology examinations seems to be very low, it is not nil [14]. On the basis of the legal and bioethical principles that pertain to informed consent, it is not sufficient for physicians simply to weigh the risks and benefits of a radiologic examination. Instead, the patient needs to be informed. Of course, this begs the important issue of the level of risk at which informed consent is indicated. Although no one doubts that informed consent should be obtained before performing a CT scan in a

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pregnant patient with suspected aortic dissection, it is not clear that it is warranted for patients undergoing routine chest radiography. Other benefits of effectively communicating the risks associated with medical radiation may be less obvious. Patients and families may be spared unfounded worry. Few data exist to document patient comprehension and beliefs about medical radiation. Just as many are probably unaware of its risks, others probably grossly overestimate the risks posed, or even fear risks that do not exist. News media reports often present the risks in unnecessarily alarming form, as in the December 19, 2009, USA Today article titled “Radiation from CT scans linked to cancers, deaths” [15]. This article begins, “CT scans deliver far more radiation than has been believed and may contribute to 29,000 new cancers each year, along with 14,500 deaths.” It is preferable that patients receive information concerning risks and benefits before their examinations, expressed in terms of frequency rather than absolute numbers with no denominators, and put in the context of the risk of not having the examination. Online resources are a growing source of medical information for patients. A Google search for “CT scan radiation” found the following question posted to the Ask the Experts section of the Health Physics Society’s Web site [16]: I am a 33-year-old woman. About three months ago I suffered from acute back pain . . . . I decided to get the opinion of my general practitioner (GP) and she suspected a prolapsed disk and said that I should get a CT scan . . . . I felt a bit nauseous after the scan was taken. I asked my GP upon return how much radiation a CT scan was compared to an ordinary x ray and she replied that “it is the same but that they make slices.” When I asked her about the effects on my ovaries she answered that she wouldn’t know. I found out the amount of radiation is 10mSv by calling the radiologist and from information on the Internet . . . . I am very afraid that I will develop bone-marrow cancer from the scan and that I won’t be able to have children . . . . I have been worrying for the last four weeks about possible radiation effects and searched the Internet for information . . . . I am afraid that I am more sensitive to the effects of radiation than other people.

It is easy to dismiss such concerns as uninformed; however, it may be representative of a significant proportion of patients. More research is needed to better understand patients’ perception of medical radiation and the risks it poses. A final justification for the effort to improve the communication of the risks and benefits associated with medical radiation is the steady progression of the expectations of patients and the legal system toward “full disclosure.” As Berlin [10] noted, “Both the public at large and the courts are continuously imposing ethical and legal duties on radiologists and other physicians to expand the nature and the amount of information that must be disclosed to patients.” It is generally preferable to initiate improvements from inside the field than wait for likely less effec-

tive and more obtrusive changes to be imposed from outside. CURRENT INITIATIVES, RESOURCES, AND OPPORTUNITIES

Communicating the risks and benefits of medical radiation has received increased attention in recent years, resulting in the introduction of new initiatives and a growing body of resources available to radiologists. Many opportunities remain for improvement. Karsli et al [17] questioned 456 referring physicians and radiologists affiliated with 3 tertiary hospitals and found that the majority of those sampled felt that informed consent should be obtained before radiologic examinations. Goske and Bulas [18] argued that “informed consent might not be necessary, not because it is too burdensome, but rather because it does not provide enough information for patients in a context that is understandable to them.” We agree that patients need to be better informed, but we are also wary of extending the modern model of informed consent as it is typically employed. Nightmare scenarios are conceivable in which radiology departments grind to a halt as they attempt to obtain informed consent for everything they do. Having patients sign a liability waiver with lists of alarming risks and confusing numbers is more likely to scare patients than empower them. Many approaches to communication have been studied, including improved consent forms [19], increased one-on-one discussion [13,20], accessory documentation [21], graphical representation of data [22], video [23-26], and interactive computer-based education [2730]. These efforts have met with varying levels of success. Some approaches seem better suited for certain types of clinical circumstances. For instance, interactive computer education may be well suited for nonemergent cardiac catheterization but not so suitable for a pregnant patient with suspected aortic dissection. Picano [31] suggested presenting risks for radiologic and nuclear medicine examinations in graphical format, advocating a clever, information-rich graph that plots several common examinations according to a linear relationship between radiation dose and the estimated increased incidence of cancer in the general population and expressing radiation dose in multiples of a chest radiograph. The poor numeracy of many patients demonstrated by Sheridan et al [12] suggests that a simpler graphic may be more widely applicable. Schapira et al [22] investigated the communication of probabilistic outcomes using various numeric and graphical representations in the setting of communicating breast cancer risk to women. They found a consistent theme “that frequency graphics using human figures were easy to identify with, were understandable, and conveyed a meaningful message.” The article includes a sample graphic with a series of 1,000

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very small human figures, with initial few figures highlighted to represent the risk frequency per 1,000 individuals. This type of format seems promising for the quick and effective communication of risk data across a wide variety of settings, including varying levels of patient education, distress, and clinical urgency. Lee et al [32] suggested that posting information in radiology departments and making informational pamphlets available to patients is warranted and that large national radiology associations are likely best suited to take leadership in production of these materials. They concluded that “dissemination of such material will be crucial to maintain the public trust in the radiology community as responsible caregivers.” An example of a wellexecuted patient education pamphlet related to the risks associated with medical radiation is “X-Rays: How Safe Are They?” published in the United Kingdom by the National Radiological Protection Board [33]. Strengths of this document include simplicity, a broad categorization of risks that avoids implying an unrealistic precision in the current risk models, a perspective relative to natural background radiation, and recognition of the fact that these tests are generally performed because the benefits greatly outweigh the risks. Bulas et al [34] advocated similar patient education materials including a brochure titled “What Parents Should Know About Medical Radiation Safety,” developed as part of the Image Gently® campaign [35]. The Image Gently campaign, launched in 2007 by the Alliance for Radiation Safety in Pediatric Imaging, has raised awareness of opportunities to lower radiation dose in the imaging of children. The Image Gently Web site has sections for patients, pediatricians, and radiologists and includes resources such as informational brochures for patients, printable cards for tracking radiologic studies children are exposed to, and guidance for pediatric imaging protocols. Recently, the ACR and the Radiological Society of North America launched a task force that is instituting the Image WiselyTM campaign, building on the success of the Image Gently campaign and extending the message to CT imaging for adults. In addition to the need to educate patients, studies have underscored the need to better educate referring physicians, demonstrating that referring physicians often have limited knowledge of the radiation dose and associated risks for common radiologic examinations [32,36-40]. This is unfortunate, for two reasons. First, this knowledge is relevant for appropriate medical decision making in ordering radiologic examinations. Second, referring physicians are well positioned to initiate patient education on the risks associated with these examinations. Referring physicians often have good preexisting relationships and well-developed lines of communication. They also should understand the benefits of the radiology examination they are

ordering for particular patients and have the opportunity to involve the patients in the decision-making process further upstream. By the time patient education can occur in the radiology department, a patient may have taken time off work and made a long trip to the radiology department, and completing the examination may be a foregone conclusion. Rosenthal et al [41] demonstrated that by incorporating instant feedback on “utility scores” on the basis of appropriateness criteria in a radiology order entry system, referring physician ordering patterns can be changed to conform better to established criteria for the appropriate use of radiologic examinations. Perhaps a similar approach would be useful here. Expected radiation exposure and basic risk estimate data provided for specific examinations when they are ordered would both inform referring physicians and help them educate patients. There are additional opportunities for improvement, including better educating radiologists on the importance of effectively communicating medical radiation risk information to patients and referring physicians and how to effectively accomplish this. More research is needed aimed at enhancing our understanding of patient comprehension of medical radiation and its associated risks and benefits, including what patients want to know and how best to communicate this information. Additionally, we need research to define how best to educate referring physicians and radiologists about medical radiation patient safety. CONCLUSIONS

Patient-physician communication and patient education in radiology is an important topic that is receiving increasing attention. A radiologist who understands why this communication is important, why it is challenging, and is familiar with the current initiatives and available resources is better positioned to serve patients. Educating the general public, patients, referring health professionals, and fellow radiologists and radiology department personnel about the risks and benefits of medical radiation is an important professional responsibility of radiologists. It is also an important opportunity to improve the quality and perception of the quality of radiologic care. Patients benefit by making better informed choices and alleviating groundless worry. Radiology benefits by providing better patient care and enhancing public trust in the field. REFERENCES 1. American Medical Association. Patient physician relationship topics: informed consent. Available at: http://www.ama-assn.org/ama/pub/ physician-resources/legal-topics/patient-physician-relationship-topics/ informed-consent.shtml. Accessed March 7, 2010. 2. Berg J, Appelbaum P, Parker L, Lidz C. Informed consent: legal theory and clinical practice. 2nd ed. New York: Oxford University Press; 2001: 14 –22.

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