Decision-Making Capacity & Surrogates
A board-focused ethics lesson on decision-making capacity (clinical, decision-specific, four Appelbaum criteria) versus legal competence, the default surrogate hierarchy, advance directives (living will vs. healthcare proxy), and the substituted-judgment/best-interest standards that drive next-best-step decisions.
Capacity vs. Competence
Decision-making capacity is a clinical judgment — any physician can and should assess it at the bedside — whereas competence is a legal status decided only by a court. On the wards and on Step 2 CK, the tested question is almost always capacity. Capacity is decision-specific and can fluctuate (delirium, intoxication, hypoglycemia), so reassess it for each decision and over time.
It rests on four abilities the patient must demonstrate (Appelbaum): communicate a stable choice, understand the relevant facts, appreciate how they apply to their own situation, and reason through the options. A mentally ill, involuntarily hospitalized, or "noncompliant" patient is not automatically incapacitated — even a refusal that leads to death (e.g., a Jehovah's Witness adult declining transfusion) must be honored if capacity is intact, because autonomy governs. Only when a patient lacks capacity do you turn to advance directives and surrogates.
- Four criteria (Appelbaum): Communicate a choice · Understand · Appreciate · Reason
- Capacity = clinical & decision-specific (any physician; reassess over time); competence = legal, decided only by a court
- Psychiatric diagnosis, active psychosis, or an involuntary hold ≠ automatic incapacity — assess the specific decision directly
- A patient with capacity may refuse any treatment, even life-saving (autonomy > beneficence)
- Fix reversible causes first: treat delirium, hypoglycemia, intoxication, pain — then reassess
- Sliding scale: higher-risk / lower-benefit decisions warrant a more rigorous capacity assessment
- Authority when incapacitated: the patient's own advance directive / appointed proxy (DPOA-HC) first → then default surrogate: spouse → adult children → parents → adult siblings → other relatives
- A court-appointed guardian is the court-designated legal surrogate; a patient-designated proxy outranks the default family list
- Decision standards, in order: (1) patient's advance directive → (2) substituted judgment (what this patient would want) → (3) best interest (wishes unknown)
- Emergency + no surrogate reachable → treat under implied consent
Capacity vs. Competence
| Feature | Capacity | Competence |
|---|---|---|
| Determined by | Any physician (clinical) | Judge / court (legal) |
| Scope | Decision-specific | Global legal status |
| Time course | Can fluctuate; reassess | Stands until changed by court |
| Typical trigger | Consent/refusal of a treatment | Guardianship, financial/legal acts |
CURVES (Chow et al., Chest 2010 — a real, published emergency-setting tool) confirms capacity and flags when to act without it:
- C — Choose and Communicate a choice
- U — Understand the risks, benefits, alternatives
- R — Reason through the options logically
- V — Value: the choice is consistent with the patient's own values
- E — Emergency? Immediate treatment needed to prevent serious harm
- S — Surrogate available to decide?
C-U-R-V map onto the Appelbaum abilities and confirm capacity; E-S guide action when capacity is absent.
Stem: A 34-year-old man with schizophrenia, hospitalized involuntarily for agitation, has necrotizing fasciitis of the leg and refuses amputation. He says, "I understand the infection will kill me without surgery, but I don't want to lose my leg," and repeats this consistently. Auditory hallucinations are present but unrelated to the decision.
Assessment: He communicates a stable choice, understands the diagnosis and consequences, appreciates that they apply to him, and reasons coherently → capacity is intact. Psychosis and involuntary commitment do not by themselves remove capacity, and a psychiatric hold does not authorize treating an unrelated medical condition over his refusal.
Next best step: Respect his refusal; continue antibiotics and supportive care, optimize pain and psychiatric management, and re-offer surgery. Do not seek a court order or override via family.
Contrast: If he said "the CIA planted the infection to test me," his delusion would corrupt appreciation → capacity lost → proceed via surrogate.
Advance Directives & Surrogate Standards
When a patient lacks capacity, honor their prior autonomous wishes first. A living will is a document stating what treatments the patient wants or refuses in specified end-of-life scenarios (terminal illness, persistent vegetative state). A durable power of attorney for health care (DPOA-HC / healthcare proxy) names a person and is generally more useful and takes precedence, because it flexibly covers situations a living will never anticipated.
If no advance directive exists, a surrogate decides using substituted judgment — reconstructing what this specific patient would have chosen from their known values and prior statements. Only when the patient's preferences are genuinely unknown does the surrogate fall back to the best-interest standard (weighing benefits vs. burdens). Critically, a surrogate cannot override a valid advance directive or a decision the patient made while they still had capacity.
Living Will vs. Healthcare Proxy
| Feature | Living Will | Healthcare Proxy (DPOA-HC) |
|---|---|---|
| What it is | Written document of wishes | A designated person/agent |
| Applies when | Specific end-of-life scenarios | Any decision once patient lacks capacity |
| Flexibility | Rigid; can't cover the unforeseen | Adapts to new situations |
| Board pearl | Honor specific instructions | Generally takes precedence; preferred |
Stem: A 72-year-old woman is unconscious after a hemorrhagic stroke and cannot make decisions. She has no living will, but 3 years ago legally named her daughter as healthcare proxy. Her husband insists on "doing everything," while the daughter says the patient told her she would never want to be kept alive on machines.
Next best step: Decision-making authority goes to the daughter (designated proxy), who applies substituted judgment from the patient's stated wishes — not the husband, despite being the spouse, because a patient-designated agent outranks the default family hierarchy.
Twist 1: Had she named no proxy and left no directive, the spouse would be the first default surrogate. Twist 2: If an emergency arose with no surrogate reachable, treat under implied consent.
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