Intended for healthcare professionals


Patients' understanding of risk

BMJ 2003; 327 doi: (Published 25 September 2003) Cite this as: BMJ 2003;327:693
  1. Hazel Thornton, honorary visiting fellow (hazelcagct{at}
  1. Department of Health Sciences, University of Leicester, Leicester LE1 7RH

    Enabling understanding must not lead to manipulation

    Who would disagree that understanding risks in order to trade them off against potential benefits is a prerequisite for citizens or patients who need to make health decisions? But rational consideration of risk, even if graphically explained1 and understood, is neither straightforward nor sufficient. Rationality is not the only component in decision making.

    Apparently irrational influences and considerations exert strong pressures. Individuals' perceptions of risk, and attitudes to it, may lead them to choices that seem irrational to the health professional. Perceptions are built up over time, informed by personal experiences and social networks, and shaped by behavioural norms and media reporting. Fear of a disease, trust in technology, and the desire to take responsibility for health also contribute to decisions people make.2

    Research shows that avoidance of regret (that an intervention was freely available but was not taken up), a perceived right to access, and pursuit of equitability are reasons given by men for accepting and recommending prostate specific antigen (PSA) testing for prostate cancer.3 Prejudices and preconceived judgments, culture, and the social context of a disease are powerful motivators, as are belief and tradition.4 American women's predilection for risk averse tactics in their choice of treatment for breast cancer can result in drastic therapeutic decisions (such as extremely toxic chemo-therapy treatments) with only 1-2% possibility of effectiveness, in the name of their right to individual control.4

    The framing of risks, both numerically and linguistically, and the value individuals place on the various gains and losses perceived, have an effect on the choices that they make.5 This has considerable ethical implications for information providers if manipulation of individuals and populations is to be avoided.6

    Gain in the short term is often an attractive choice, even if it comes with later loss.7 For example, many women use hormone replacement because they believe that the relief from debilitating and persistent daily menopausal symptoms now is worth the increased risk of breast cancer later. Many have stayed with their decision, even after recent headline news in the media reporting new evidence that heightens the risk.8 This is in spite of the fact that women generally grossly overestimate their risk of getting breast cancer and of dying of it.9

    Good quality information and graphics are needed to explain risks associated with medical conditions and options–for patients in consultation with their doctors, but increasingly also for members of the public attempting to take responsibility for their own health.1 Pressures from many sources advise individuals to strive for health and prevent disease by various stratagems, from supplements to screening. Sometimes a series of risks, contingent on possible different courses of action, has to be considered and traded off against likelihood of possible benefits, both near term and long term. Each possible course of action will contain its own trade-off of harms and benefits. Research has shown that consultations in which doctors have been trained in the use of decision aids sharpened the focus of the consultation, changed the content, and resulted in greater perception of decisions actually being made.10

    Even if patients have received the benefit of a clear explanation about a particular risk, their expectations and attitude to that risk will affect their perception of it: what one patient will deem acceptable, another will not. Patients may alter their opinion at different stages of their disease: if the stakes increase, a greater risk might be thought worth while. A drug used for prevention has a very different trade-off value from one used for early stage disease or for metastatic disease.11

    Knowing and understanding the frequency of an event in a population provides no certainty for individuals–only a guide to be used according to their own circumstances, values, and preferences. Accepting uncertainty is probably the most difficult aspect for any patient.12 Fear disturbs the balance between rational and irrational behaviour. Taking responsibility for decisions is not easy but can be helped by sharing the process with a skilled and sensitive health professional.10

    The business of enabling patients to understand risk so that they might incorporate it into their decision making processes is fraught with difficulties. It goes without saying that health practitioners need the knowledge, skills, confidence, communication skills, and the decision aids to provide this essential component of shared decision making. 10 Few interventions are risk free.

    Those charged with the governance of risk in society will need to widen their research in partnership with users, to examine social factors that go beyond the cognitive to the behavioural, including the social context in which meanings are shaped. This will require attitudinal shifts in policy makers, patients, purchasers, and professionals, with potential consequences that are far reaching for individuals, health services, health economics, and society.


    • Competing interests None declared.


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