The limits of shared decision making

To cite: Elwyn G, Price A, Franco JVA, et al. BMJ EvidenceBased Medicine Epub ahead of print: [please include Day Month Year]. doi:10.1136/ bmjebm-2022-112089 © Author(s) (or their employer(s)) 2022. Reuse permitted under CC BYNC. No commercial reuse. See rights and permissions. Published by BMJ. The foundation of shared decision making (SDM) is the view that people should be aware of relevant choices, and that their personal views, priorities and preferences are relevant factors when determining action. The degree to which people wish to engage in decisions will vary, as will the level to which they will be made aware that decisions exist, or become informed about the relevant information. There is increasing interest in SDM, an ethical imperative, and supporting evidence that welldesigned tools help people compare options and make more informed choices. We as authors, are strong advocates of SDM, and think the approach can be applied widely, perhaps more widely than many health professionals think possible. 5 Nevertheless we have identified situations where we consider there to be clear limits to SDM, where wider interests can override the priority given to individual preferences. While we think individual priorities and preferences should be respected where possible, there are situations where other factors determine decisions. We feel it is essential to make these situations clear. SDM can be too easily dismissed as an impossible ideal if we do not acknowledge that the approach has limitations. In addition, delineating exceptions will serve to illustrate the demarcation between what can be thought of as the pinnacle of patientcentred care and situations where the approach is rightly constrained by ethical, professional or societal factors. First, let’s agree that decisions come in different forms: some are conscious and episodic, as in ‘Shall I have this procedure?’. Some are the result of commitment decisions, such as when agreeing to take medication for a longterm illness. Others go unnoticed in conversations, such as when a clinician suggests a solution and results in assumed acceptance. Such subtle decisions may well occur because of deference to an expert or an unwillingness to disagree. SDM makes the process of determining decisions more explicit, and in healthcare the skills of supporting people to become aware, consciously deliberate, and arrive at betterconsidered decisions, whether for irreversible or continuous actions, are of utmost value. The steps suggested to achieve SDM have been extensively described elsewhere. It therefore follows that SDM can be applied to a wide range of situations. When there is no evidence that any one management option is considered superior to another reasonable option, then SDM could be seen as a necessary approach. This situation has been described as one where clinical equipoise exists. Indeed, it might even be considered unethical not to provide information about alternatives in such situations. 13 More common, however, is the situation where a range of options exist and where the extent of evidence, and its quality, varies considerably, exacerbating uncertainty. Sometimes the evidence is sparse or poor, or points in different directions, yet there are reasonable options, including the potential watchful waiting or taking no action. Sometimes there is good evidence and high certainty, but even so there are important tradeoffs to consider, such as side effects, or other burdens and costs. In these scenarios, individual preferences will contribute to an assessment of what action to take. To the degree that it is reasonable to compare options, these situations also qualify as having clinical equipoise. SDM is necessary because there will always be a need to consider harms alongside benefits, and critically, the weighting of those factors will vary according to the priorities and preferences of people who will live with the consequences of decisions made, and the tradeoffs they are willing to make. However, there are also situations where taking a shared approach to decisions is not possible, although this does not rule out the need to provide empathetic care. There are limits to SDM, and the goal of this article is to be clear about the type of situations where SDM faces limits and where other strategies will need to be considered. Limits on SDM will occur when: ► Wider interests override individual wishes ► Evidence of benefit is insufficient or absent ► Lowered decisional capacity is present ► Profound existential uncertainty exists.