Capacity and best-interest decisions in frailty

Synopsis

Make lawful, person-centred decisions in frailty by presuming and supporting capacity, testing the specific decision functionally, distinguishing unwise choice from inability and using advance decisions, authorised representatives and transparent least-restrictive best-interests reasoning when capacity is absent.

• Age, frailty, diagnosis, care-home residence and an unwise decision never establish incapacity; start with a presumption that the adult can decide.
• First-line capacity assessment defines the exact decision and material information, provides communication support and checks understanding, retention, use or weighing and communication.
• Capacity is time and decision specific. A person may decide about antibiotics but not a complex residence plan, and delirium may justify delay until capacity improves when safe.
• Document the causal impairment or disturbance of mind or brain and how it produces inability under the applicable legal test; poor memory alone is insufficient.
• If capacity is present, respect the informed choice even when professionals or relatives disagree, while offering harm reduction and review.
• If capacity is absent, check valid advance decisions, registered health-and-welfare attorney or court-appointed authority before convening a best-interests process.
• Best interests considers clinical benefit and burden, past and present wishes, values, beliefs, relationships, less restrictive options and the views of appropriate people; family do not vote on the outcome.
• Following [2026] UKSC 16, lack of domestic decision-making capacity about residence or care does not by itself prove inability to consent for Article 5 purposes; examine current wishes, feelings and basic understanding of the confinement separately.
• In England and Wales, an IMCA may be required for serious medical treatment or accommodation decisions when the person lacks capacity and has no appropriate unpaid representative.
• Emergency treatment necessary to preserve life or prevent serious deterioration can proceed in best interests when delay is unsafe, using the least restrictive option and documenting the rationale.
• Scotland and Northern Ireland use different statutory frameworks and terminology; apply the law where care occurs rather than treating the Mental Capacity Act 2005 as UK-wide.