Decision-Making Capacity and Competence

• Four components, all of which must be present:

1. 1.Communicate a choice, and hold it with reasonable consistency.
2. 2.Understand the relevant information — diagnosis, treatment, risks, alternatives.
3. 3.Appreciate how that information applies to one's own situation.
4. 4.Reason — manipulate the information to reach a decision consistent with one's own values.

• Capacity is decision-specific and time-specific. A patient may lack capacity to consent to complex surgery while retaining capacity to refuse a blood draw, and delirium fluctuates.
• A psychiatric diagnosis does not by itself remove capacity, and neither does making a choice the physician disagrees with. Disagreement is a prompt to assess reasoning, not evidence of incapacity.
• When capacity is absent, decisions follow a hierarchy: a previously expressed wish or advance directive, then substituted judgement by a surrogate (what this patient would have wanted), then best interests.

The four abilities (Appelbaum framework)

• Communicating a choice: the patient can state a decision and does not reverse it so often that no stable preference exists. Mutism, catatonia, or profound aphasia defeats this element first.
• Understanding: factual comprehension of diagnosis, proposed intervention, risks, benefits, and alternatives including no treatment. Tested by asking the patient to paraphrase, not by asking "do you understand?"
• Appreciation: the patient applies those facts to himself. The classic failure is delusional or denial-based — "the biopsy is cancer, but not in my case." Appreciation, not understanding, is what psychosis and frontal-lobe disease most often destroy.
• Reasoning: the ability to weigh options against personal values and generate a rationale. The rationale need not be one the physician shares; it must be internally coherent and value-consistent.

Distinctions that carry the topic

• Capacity vs. competence: capacity is a bedside clinical judgment made by the treating physician for a specific decision at a specific time; competence is a global legal status removed only by a judge, who then appoints a guardian/conservator.
• Decision-specific, not global: the threshold rises with the risk–benefit asymmetry of the choice (the commonly taught sliding scale). Consenting to a low-risk, high-benefit antibiotic requires less demonstrated reasoning than refusing it.
• Informed consent (AMA Code of Medical Ethics, Opinion 2.1.1) requires capacity, disclosure, understanding, and voluntariness — coercion by family or institution invalidates consent even in a fully capacitated patient.
• Surrogate standards (AMA Opinion 2.1.2, and the Uniform Health-Care Decisions Act model followed in varying form by states): an advance directive or durable power of attorney for health care controls first; otherwise the surrogate applies substituted judgment, falling back to best interests only when the patient's prior wishes are unknown.
• Structured tools such as the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) and the Aid to Capacity Evaluation operationalize the four abilities but supplement, never replace, the clinical interview. A Mini-Mental State score is not a capacity determination.

• Step 1 — screen for a reversible cause. Check for delirium (fluctuating attention, sleep–wake reversal), hypoxia, hypoglycemia, uremia, infection, intoxication or withdrawal, and sedating medications. Capacity is time-specific; a patient who is obtunded at 2 a.m. may be assessable at 10 a.m. Treat the reversible cause and reassess before declaring incapacity.
• Step 2 — remove communication barriers. Use a professional interpreter, hearing amplification, or written materials. Lack of English proficiency or low health literacy is a disclosure problem, not incapacity — an obligation The Joint Commission frames as effective patient communication.
• **Step 3 — apply the four abilities to this decision. He communicates a stable choice, restates the diagnosis and the mortality risk (understanding), acknowledges the gangrene is his own (appreciation), and weighs survival against a valued mode of living (reasoning). He has capacity, and his refusal stands.**
• Step 4 — recognize the distractors. Disagreement with the surgical team is not incapacity. A history of depression is not incapacity. A psychiatry consult may be requested for ambiguity, but no consult and no court is required for the physician to make this determination.
• Contrast: if the same man instead said, "my foot is fine, that black color is shoe polish," appreciation fails. Now the sequence is: look for an advance directive or health care proxy, then the state-designated surrogate (typically spouse, then adult children, then parents, then siblings), applying substituted judgment. If he were unconscious, septic, and no surrogate were reachable, the emergency exception permits life-saving treatment under presumed consent.
• Document the specific questions asked and answers given — a conclusory note reading "patient lacks capacity" is indefensible.

• The single most tested distinction: capacity = clinical, made by any physician, decision- and time-specific; competence = legal, removed only by a judge. If the answer choices include "obtain a court order" for a straightforward bedside determination, it is almost always wrong.
• Psychiatry consult is optional, not mandatory. Correct when the picture is ambiguous, when psychosis or severe depression may be distorting appreciation, or when the team is conflicted — not as a prerequisite for every refusal.
• Refusing recommended care is not evidence of incapacity. Neither is a psychiatric diagnosis, dementia labeling, an odd religious belief, or a low MMSE score. Assess the four abilities for the decision at hand.
• Appreciation is the ability most often lost in psychosis, mania, anorexia nervosa, and frontal-lobe injury: the patient recites the facts perfectly yet denies they apply to him. Look for this in stems where the patient "understands" but says "that won't happen to me."
• Involuntary psychiatric hold ≠ loss of treatment capacity. A patient committed for dangerousness or grave disability may still retain the right to refuse non-emergency medication in most jurisdictions; forced medication generally requires a separate legal or administrative process. This is a favorite distractor.
• Delirium fluctuates — reassess during a lucid interval, and correct hypoxia, hypoglycemia, infection, uremia, intoxication, and deliriogenic drugs (anticholinergics, benzodiazepines, opioids) before concluding a patient lacks capacity.
• Hierarchy when capacity is absent: the patient's own valid, applicable advance directive or clearly expressed prior wish controls first → then the agent named in a healthcare proxy/durable power of attorney, who interprets where the directive is silent → then a court-appointed guardian, if one exists → then the statutory surrogate applying substituted judgment → then best interests. The AMA Code of Medical Ethics (Opinion 2.1.2) frames this as following the patient's known preferences/advance directive, then substituted judgment, then best interests; the surrogate priority list and guardian-versus-agent precedence are set by state statute (under the Uniform Health-Care Decisions Act model, a patient-designated agent generally takes priority over a guardian). Substituted judgment asks what would this patient have wanted, not what the family wants.
• Emergencies: implied consent permits immediate life- or limb-saving treatment when the patient lacks capacity and no surrogate is available. Emancipated minors — married, active-duty military, or declared emancipated by a court; some states also recognize financial independence or parenthood, and categories vary by state — consent for themselves, and most states allow minors to consent independently for STI, contraceptive, pregnancy, and substance use care.