Professional Role · Topic 7 of 26
Informed Consent & Decision-Making Capacity
Tap any line to see why it matters
Informed Consent & Decision-Making Capacity
Valid consent needs a capable patient, full disclosure and a free choice. Capacity is decision-specific and judged by the treating clinician, not a court.
Capacity: four abilities
Capacity is decision-specific — judged by the treating clinician
When to formally assess capacity
Clinicians under-recognize incapacity, identifying only about 42% of patients found incapable on formal evaluation; incapacity affects about 26% of medical inpatients versus about 3% of healthy older adults.
Assess capacity, in order
The Aid to Capacity Evaluation (ACE) improves accuracy. A cognitive screen such as the MMSE helps only at its extremes and cannot by itself establish or exclude capacity.
Capacity rules
Capacity fluctuates: delirium, intoxication, hypoxia, metabolic derangement, medication effects and acute psychiatric illness can remove it temporarily. A patient with dementia may also name a surrogate yet lack capacity for high-risk surgery. A capable Jehovah's Witness refusing blood products is honored. The final determination stays with the treating team.
Informed consent: what to disclose
Valid consent = capable patient + full disclosure + free choice
Withholding pertinent information because disclosure seems harmful ("therapeutic privilege") is ethically unacceptable except in emergencies when the patient cannot make an informed decision; patients may choose to delegate information and decisions. Decision aids (graphics, videos, interactive programs) improve knowledge of options and reduce decisional conflict.
Implied or express consent?
Implied consent is enough
Express informed consent
Getting consent right
Federal law requires reasonable steps to communicate with patients who do not speak English or have other communication barriers.
Refusal and emergencies
Refusal is not suicide, even if death results. If a refusal would harm others, such as a dependent minor child, seek ethics and legal consultation.
Capacity cannot be restored
The health care agent is the one named in a durable power of attorney for health care. When a patient judged clinically incapable still voices a preference, the clinician often cannot override it without a court finding of legal incapacity; supported decision-making agreements are a less restrictive alternative to guardianship.
Capacity or competence?
| Decision-making capacity | Legal competence | |
|---|---|---|
| Who determines it | The treating clinician | A court (judge) |
| Scope | One specific decision | Some or all areas of life, as the court orders |
| Over time | Fluctuates — treat reversible causes and reassess | Presumed until a judge declares incapacity |
| When it is lacking | Agent or default surrogate decides | Court-appointed guardian or conservator decides |
Minors and young adults
Capacity is judged one decision at a time — and disagreeing with the clinician is not incapacity.
Sources · Informed Consent (Merck Manual Professional) · Capacity (Competence) and Incapacity (Merck Manual Professional) · Consent and Surrogate Decision Making (Merck Manual Professional) · Evaluating Medical Decision-Making Capacity in Practice (AFP 2018) · AMA Code of Medical Ethics Opinion 2.1.1 — Informed Consent · Appelbaum PS. Assessment of Patients' Competence to Consent to Treatment (NEJM 2007) · AMA Code of Medical Ethics Opinion 2.1.3 — Withholding Information from Patients · Got Transition. Six Core Elements: transitioning youth to adult · White PH, Cooley WC; AAP, AAFP, ACP. Supporting the Health Care Transition From Adolescence to Adulthood in the Medical Home. Pediatrics 2018 · Got Transition. Six Core Elements of Health Care Transition (overview and timeline) · Follow your institution's protocols.