Decision-Making Capacity and Surrogacy

Decision-making capacity is a person's ability to make a specific medical decision at a specific time, conventionally framed around understanding relevant information, appreciating how it applies to oneself, reasoning about options, and communicating a choice. When capacity is lacking, surrogate decision-making takes over, in which a designated or default representative makes decisions on the patient's behalf. Both are pivotal in geriatric and end-of-life care, where cognitive impairment is common.

Definition

Decision-making capacity is the clinically assessed ability to make a particular medical decision, generally described through the abilities to understand, appreciate, reason, and express a choice; surrogacy is the arrangement by which an authorised representative makes medical decisions for a patient who lacks capacity, typically guided by substituted judgment or, failing that, the patient's best interests.

Scope

This topic covers the concept and components of decision-making capacity, how it differs from the legal notion of competence, and the framework of surrogate decision-making, including substituted judgment and best interests. It is a conceptual reference. It does not provide a tool, threshold, or protocol for judging a particular patient's capacity, which is a clinical and sometimes legal determination.

Core questions

• What are the recognised components of decision-making capacity?
• How does capacity differ from legal competence, and why is it decision-specific?
• Who serves as surrogate, and on what standard do they decide?
• How accurately do surrogates predict patients' wishes, and at what cost to themselves?

Key concepts

• Understanding, appreciation, reasoning, and expressing a choice
• Decision-specific and time-specific capacity
• Capacity versus legal competence
• Surrogate decision maker (proxy)
• Substituted judgment standard
• Best interests standard
• Surrogate accuracy and decision-making burden

Mechanisms

Capacity is commonly assessed against four abilities: understanding the relevant information, appreciating its significance for one's own situation, reasoning about the options, and communicating a choice; it is judged for a specific decision at a specific time, so a person may have capacity for one decision but not another (Appelbaum, 2007). When capacity is absent, a surrogate decides, ideally by substituted judgment, reconstructing what the patient would have wanted, and otherwise by the patient's best interests. Surrogates' predictions of patients' wishes are imperfect, and the role can impose a lasting emotional burden, findings that inform how surrogacy is supported (Shalowitz, 2006; Wendler, 2011).

Clinical relevance

This entry explains how capacity and surrogate decision-making are conceptualised so readers can understand who makes decisions, and on what basis, when a patient cannot. It is reference-educational and non-prescriptive: determining an individual's capacity or the proper surrogate is a clinical and legal judgement that this entry does not provide.

Epidemiology

Impaired decision-making capacity is common near the end of life and in older adults with dementia or delirium, so surrogate decision-making is frequently required. A systematic review found surrogates predicted patients' treatment preferences with only moderate accuracy (Shalowitz, 2006), and another found that serving as a surrogate often imposes a substantial and sometimes lasting emotional burden (Wendler, 2011).

Evidence & guidelines

Capacity assessment is widely described through the four-abilities model articulated by Appelbaum (2007). Systematic reviews characterise the limits of surrogate accuracy (Shalowitz, 2006) and the burdens surrogates experience (Wendler, 2011). These findings have motivated approaches to advance care planning that prepare surrogates to make decisions rather than relying solely on written directives (Sudore, 2010).

History

The contemporary clinical concept of decision-making capacity, distinct from the legal status of competence, was consolidated through work on informed consent in the late twentieth century, with the four-abilities framework becoming a standard reference (Appelbaum, 2007). Attention later turned to the validity and human cost of surrogate decision-making, prompting systematic study of surrogate accuracy and burden (Shalowitz, 2006; Wendler, 2011).

Debates

How reliable is surrogate substituted judgment?

Surrogates predict patients' preferences only moderately well and may bear a heavy emotional burden, raising questions about how much weight substituted judgment should carry and how best to support surrogates and prepare them in advance.

Key figures

• Paul Appelbaum
• Thomas Grisso
• David Wendler
• Rebecca Sudore

Seminal works

• appelbaum-2007
• shalowitz-2006

Frequently asked questions

What is the difference between capacity and competence?

Capacity is a clinical judgement about a person's ability to make a particular decision at a particular time and can vary by decision. Competence is a legal status, usually determined by a court. In practice clinicians assess capacity; competence is a formal legal designation.

What standards guide a surrogate's decisions?

A surrogate is generally expected to use substituted judgment, deciding as the patient would have decided based on their known values and wishes. When those are unknown, the surrogate is expected to act in the patient's best interests.