VIEWPOINT
Viewpoint
Communication of risk: choice, consent, and trust Kenneth C Calman Communication of risk is complex and multifaceted, and is the communication of the probability and uncertainty that a particular hazard will cause an effect.1–3 Three factors are relevant in such communication; the certainty of the risk (the evidence base), the level of risk (high or low), and the effect of the risk on the individual or population. Risks can therefore range from hypothetical risk (possible, biologically plausible, but no evidence of certainty, level of risk, or its effect) to clearly identified (certainty established, level defined, and effect assessed). However even in this latter case, the risk to the individual remains a probability. Communication is most difficult when the risk is unknown. Two examples should clarify the distinction and the consequences of risk analysis.5 The first example is hepatitis B. That patients could contract this disease from transfusion is not only biologically plausible, but such events have also been well documented. Concentrations of the virus can be measured in blood, and the level of risk can be calculated from this measurement. The consequences are known, and the blood can be screened and affected units discarded. The risk can thus be reduced. By contrast, although variant Creutzfeldt-Jakob disease could plausibly be transmitted in blood, the prion cannot be routinely measured in blood, and thus the level of risk cannot be assessed. The consequences of infection are well recognised if they arise. In this example, neither the certainty (the evidence base) nor the level of risk are known, but action would still be possible and precautions could be taken. However, the precaution is not to use blood, and thus the risk of infection would be replaced by other risks; a patient who is seriously ill might either not be given blood or might be given another source that has other consequences. Here, I discuss how such difficult issues should be communicated to patients and the public.
Communication of risk In communication of risk, the following issues need to be considered: the objectives and purpose of the communication; the difficulty of uncertainty and the unknown; the issues of choice, consent, and trust; and the perception of risk. The purpose of communication of risk The main reason for communication of risk is to provide the individual or community with sufficient information to make choices about the consequences of the risk and thereby assist in deciding which action or actions, if any, are to be taken. The language used (the “framing”) is crucial and can affect the choice made.6–8 The process of communication is dynamic, and the public is not just a passive recipient of information. The difficulty of uncertainty and the unknown The process of risk communication can be divided into three phases; anticipatory—a potential hazard can be identified but there is no, or limited, evidence of an effect; communication—most of the public attention is focused, Lancet 2002; 360: 166–68 University of Durham, Old Elvet, Durham DH1 3HP (K C Calman MD) (e-mail:
[email protected])
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and is in clinical terms the phase of breaking bad news; and learning—the professional or institution actively learns from the process. The anticipatory phase is the most difficult to manage and to communicate, but is generally discussed less than the other phases. Every phase is relevant to clinical and public health issues. In the first part of the anticipatory phase, it is assumed that a problem might exist, but there is no evidence to support such an assumption. It is a phase of hypothesis, presumption, supposition, or suspicion. It is important to remember this because as the information accumulates, the supposition becomes confirmed, or refuted, by evidence for or against. In the initial period, any action taken would be based on the precautionary principle, since the evidence for risk is unknown. In the second part of the anticipatory phase, when evidence becomes available, then action (or no action) can be taken on the basis of this information. These parts are distinct, but overlapping, and the response to each is different. As evidence (often conflicting) accumulates, the transition period between the two parts can be difficult to manage. Relevant to this is the assumption that suspicion of a risk will always lead to an accumulation of evidence that will confirm the suspicion. However, not all suspicions are founded, and those that are not can lead to difficulties in communication. Yet the perception of a risk can remain, and the patient or the public might not be convinced that there is no problem, even if the evidence against is overwhelming. Consider the debate on use of the mumps, measles, and rubella (MMR) vaccine.9–11 An hypothesis was presented, which suggested that the MMR vaccine might be associated with development of Crohn’s disease or to autism. At first, the evidence was limited, but as data accumulated,12 it became clear that there was no evidence lending support to a link between the vaccination and these diseases. Despite this accumulation of evidence against the link, the perception that there is a link remains. Uncertainty is well known in clinical practice, in which the clinical suspicion of a disease may become confirmed as information from clinical examination and investigations emerge. It is the classic time for a discussion on truth-telling and how soon suspicion should be communicated—before or after confirmatory evidence is available. After all, as discussed above, the tests might be negative. Risk, choice, and consent An interesting comparison can be made between communication of risk to individual patients and to the population. Much has changed in the past few decades— patients are now given more information, are alerted to the risks, and are able to discuss choices. A second opinion can be sought, and the final choice made by the patient is based on an understanding of the issue, and consent is given. The difficulty during the suspicion phase has already been alluded to. Although much can still be done to improve the process of communication, much has been achieved, and it is worth noting that the process has done nothing to diminish the role of the doctor, and has probably enhanced it. Consent and trust are integral parts of the consultation process. THE LANCET • Vol 360 • July 13, 2002 • www.thelancet.com
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VIEWPOINT
Consultation with the doctor means that patients are provided with information so that they can make choices. How do the same principles operate in public health and safety? Again, the difficulty resolves itself into the two periods of the anticipatory phase. The first when there is no evidence, only suspicion, and the second as the evidence, for or against, accumulates. During the early period, research will probably be being undertaken, and some information may be available from animals or in-vitro systems. A key part of this period is to establish whether the hypothesis is biologically plausible, and whether an effect could arise. At this stage, as with the clinical situation, the public could be informed of the suspicion or possibility of a risk that might or might not be subsequently proven, informed of the results of research as they develop, and given the views of outside experts. Action can be taken to reduce any possible risk, even though there is no evidence on which to base the actions. In such circumstances, such action would be a suitable and proper use of the precautionary principle.13 For example, in the early stages of the HIV epidemic, that some kind of new disease had arisen was clear. Exactly what the disease was and how it might be spread was not evident. Advice and information were not easy to give—not enough was known. However, as evidence built up, communication became clearer, and actions could be taken. The difference between this process and the clinical one are worth noting. First, the public and the organisation or institution generally have no or few opportunities to discuss the issue. Second, the public has few opportunities to take part in the decision making process and in the choice of action to be taken. Finally, the whole process is based on the level of trust between the public and the organisation. Social trust is central to this issue. The process of communication of risk to the public could be compared with the clinical consultation process of 50 years ago. The process described above is not inherently wrong—it is a perfectly justifiable way of proceeding. Someone takes responsibility on behalf of the public to make decisions for them. Commercial organisations, the UK National Health System, and the parliamentary system, all work in this way. Trust is implicit, and that the organisation will act in the best interests of the population is assumed. Such a system is at the heart of the democratic process. What then has changed? The public has rightly become more critical of those who make decisions on their behalf. The media and electronic communication networks bring difficulties to the attention of the public more rapidly than previously. The public is also more suspicious of science, and aware of its limitations. People want to be included in decision-making, not just told what to do, and the level of trust has fallen. Once again the analogy with the clinical process is clear, but two major differences should be highlighted. First, the public is not a homogeneous group who all feel the same about an issue of public health or safety—in almost any public issue, some groups will probably disagree with the proposed outcome. Second, public health measures are imposed on individuals for their own good and for that of the wider public—there is no choice, and consent is not specifically sought. Perception of risk It is often assumed that as evidence for or against a specific hazard builds up, the public will make rational choices, and their actions will take the evidence into account. This is clearly not true, or 25% of adults in the UK would not continue to smoke and reject the evidence of smoking’s harmful effects. The converse is also relevant. Once a
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hypothesis has been developed, reversal of opinion is difficult, even if all subsequent evidence is negative. Subsections of the population will continue to believe the earlier work. Such a response is both understandable and reasonable, but makes policy making difficult. I therefore make the obvious point that changing of behaviour and beliefs is not dependent on the evidence alone—other issues matter. The history of science and medicine is full of examples of individuals who have challenged conventional wisdom, who have fought against prejudice and ignorance, and who have changed the way in which a subject is considered. What is sometimes forgotten, is that many others have pursued a course with equal vigour and persuasiveness, but their views have subsequently been found to be incorrect. How can we distinguish between the two? How do we know which voice to listen to? Who is the true or false prophet? One of the difficulties is that no evidence of an effect is not evidence of no effect. Proving a negative is difficult. In time, the answer will become clear, but can we afford to wait? What should we do while views still differ?
A way forward I have raised two main issues: in what way do the public have choice in issues of public policy, and how can they give consent to a policy if they disagree with the evidence? Clearly these questions have no easy answers, and the following proposals do no more than to begin the process of dialogue. My proposals are based on three principles. First, the public has a right to know the evidence on which decisions are based. Second, if they disagree with the policy, then they should be aware of the consequences of their decision. Third, individuals will not be allowed to opt out of some aspects of health and safety. The notion of trust is relevant to each of these. The issue can be approached in several ways. Enhancing the debate Panel 1 shows some possibilities that could assist in discussion, the purpose of which is not to support one view or another, but to try to achieve what is best for the patient or the public.
Panel 1: Possibilities for enhancing the debate Continue to collect more data and await the results, including long-term monitoring of patients and populations Such an action is will probably give the answer in the long term, but there will be dissent in the interim. During the waiting period, harm could result, although harm could also result if premature action is taken. The risk would be shifted, displaced, but not removed. For example—the closure of the railway system in England in 2000–01 probably shifted risk of death and injury from the rails to the roads. Encourage dialogue and debate Such action is appropriate, but with fixed views on both sides, and with the intervention of the media, this process is unlikely to change minds. Give into the pressure group This is the easy alternative but might be wrong and dangerous and even increase risk. Set up an independent commission This response could be helpful, but unless all parties are prepared to agree to the outcome, it may serve little purpose other than providing more time for results to accumulate.
Such options are interesting, but they do not resolve the difficulty of those who do not agree with the policy.
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VIEWPOINT
Tackling consent If the purpose of communication is to allow choice on matters of public health and safety, how would a more formal approach to consent assist the process? How could consent be explicit, voluntary, and genuine? How could consent be given? Panel 2 outlines three possible scenarios.
The importance of trust The importance of trust in this process has already been emphasised. But what do we mean by trust? A review15 has identified certain characteristics and proposes the following definition: “Trust emerges from the identification of a need that cannot be met without the assistance of another and some assessment of the risk involved in relying on the other to meet this need. Trust is a willing dependency on another’s actions, but is limited to the area of need and is subject to overt and covert testing. The outcome of trust is an evaluation of the congruence between expectations of the trusted person and actions.”15
Panel 2: Scenarios for tackling consent Consent is given, as at present, by elected bodies, ministers, and the parliamentary process This is a form of surrogate consent, and is a system that has operated well, with the interests of the population as the main motivation. Consultation with the public Public consultation would mean that around 30 million adults in the UK would have to be given sufficient information on a topic to make a choice. Such consultation would be entirely possible with electronic methods, however, there would probably not be unanimity in the outcome, and the public would have to accept the view of the majority. One or more groups would be left dissatisfied, having expressed a choice that was not used. Use an independent elected body (a public health board) who could meet rapidly and give consent on behalf of the public Another form of surrogate consent, which might also be adopted by non-governmental bodies.
There could be other models, but they will all have the same difficulty—that of a small group of people making choices on behalf of others. If trust exists, this is a legitimate process for consent. If it does not, the process could lead to disharmony and discord. Such a process is, however, the political process. Governments make decisions and policies on the economy, education, welfare, defence, and other issues, even though many people disagree.
Two metaphors are often used to describe trust, that of a journey, or of a building. Trust describes a relationship between two or more people, or between a person and an institution. To begin the journey or lay the foundations, requires definition of a series of characteristics which might include truth, openness, and sharing; respect for the views of others and tolerance; the rights of others to make decisions and autonomy; doing your best for others, not doing harm; keeping promises; sharing difficult times together. Following such principles does not mean that nothing does, or could, go wrong with the relationship. What it does mean is that if trust has been established, then the problems that arise will be easier to deal with. Trust is not easy to establish, especially for a public body. However it is very easy to lose. The old proverb captures this clearly. “Trust come on foot and goes on horseback.” Conflict of interest statement None declared.
References 1
Dealing with dissent Another approach to the issue would be to provide an alternative to those who dissent from the general view. Their choice could be accommodated under some circumstances: they would not get the procedure under the public service system; they would have to pay for the procedure; they would have to formally consent to the alternative procedure and accept the risks and consequences; the process would not be allowed if there were serious risks to public health as a whole. The last issue is crucial. If the alternative procedure jeopardised public health, then opting out would not be allowed, and if the agreement were broken, it would carry some form of penalty. Drinking and driving would be an obvious example of this, it would not be possible to opt out. Thus, any opting out would generally be related to an action or procedure affecting an individual directly, and might not be appropriate to issues such as food safety, air and water quality, vaccination, and environmental issues. Many assume that invoking the precauionary principle will always be beneficial. However, in many situations the risk is simply shifted to somewhere else.14 A recent example would be the reversal of the decision to use disposable instruments in tonsillectomies to prevent transmission of vCJD because of major side-effects.
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