Who May Consent for Another, and on What Authority

Part of Consent and Vulnerable Populations: Consent by a Legal Representative.

About 5 minutes. Free, in your language, no account needed.

Why this matters

When a person cannot consent for themselves, someone else may be able to consent on their behalf. Who that is, and what makes their authority real, is national law, and it differs more between countries than almost anything else in clinical research.

A sponsor running a trial in an incapacitated population across eight countries has eight answers, and assuming any one of them applies elsewhere is a serious error: it produces participants enrolled on the authority of someone with none.

The terminology, and why it varies

Regulation (EU) No 536/2014 uses "legally designated representative" and defines it as a natural or legal person, authority or body which, according to the law of the member state concerned, is empowered to give informed consent on behalf of an incapacitated subject.

Note what that definition does. It does not say who the representative is. It refers the question to national law, which is the honest construction, and it is why a European multi-country trial has as many answers as it has member states.

Elsewhere the terms include legally authorized representative, surrogate decision-maker, next of kin, proxy and guardian, and the terms are not interchangeable even where they overlap.

The categories of authority

Across jurisdictions, authority to consent for another generally arises in one of four ways.

A court-appointed decision-maker: a guardian, deputy or conservator appointed with defined powers. The strongest form, and it must be checked that the appointment actually covers medical or research decisions, because many do not.

An instrument executed by the person while they had capacity: a power of attorney, health care proxy or advance directive naming someone. Again, the scope matters, and many such instruments cover treatment decisions and say nothing about research.

A statutory hierarchy: national law names who may act, typically a spouse, then an adult child, then a parent, then a sibling, in a defined order. Common, and the order and the categories vary.

A clinician's determination in some jurisdictions, particularly in emergencies, where an independent physician not involved in the trial may authorize inclusion.

What must be established and recorded

That the participant lacks capacity for this decision, assessed and documented as its own finding.

Who the representative is, by name and by relationship or appointment.

On what basis they hold authority, naming the legal route.

That the basis was verified, not asserted. A court order seen and its scope noted. A power of attorney reviewed. A statutory relationship confirmed. "Daughter" recorded without establishing that the jurisdiction's hierarchy places a daughter in that position, and that no one ranking higher exists, is an assertion.

That the representative understood, and consented voluntarily, to the same standard as any participant.

The most common failure

A family member is present, concerned, obviously acting in the person's interest, and signs.

They may have no legal authority at all. A spouse is not automatically a legal representative in every jurisdiction, an adult child frequently is not, and a person who has cared for someone for decades may have less standing than a relative who has not been seen in years.

The failure happens because the alternative feels absurd. The person who knows the participant best is in the room, and refusing their signature in favor of a legal process feels like bureaucracy obstructing good care.

It is nonetheless the difference between a lawfully enrolled participant and one who is not, and the determination has to be made against the jurisdiction's actual rule rather than against what is reasonable.

In practice

A sponsor runs a trial in severe dementia across six countries. The regulatory lead and the study team produce a one-page sheet per country before any site activates.

Who may consent, in what order. What document evidences it. Whether a court appointment must cover research specifically. Whether an existing power of attorney is sufficient. What the site must see and retain.

Six sheets, and they differ substantially. In two countries a statutory hierarchy applies and a spouse may act. In two, a court-appointed representative is required and a family member cannot act however close. In one, an existing power of attorney suffices only if it expressly mentions research. In one, an independent physician's involvement is required alongside the representative.

Without the sheets, every site would have done what seemed reasonable, and in three of the six that would have been wrong.

What this looks like when it goes wrong

A participant with advanced dementia is enrolled. His daughter, who manages his care and visits daily, consents.

The applicable law requires a court-appointed representative for research participation, and no such appointment exists.

The daughter acted in good faith and in her father's interest. The site acted reasonably. The participant has been enrolled in a trial without consent from anyone entitled to give it.

This is not curable retrospectively. Obtaining a court appointment now does not validate the enrollment that already happened, and every procedure performed to date was performed without valid consent.

The requirement was findable. Nobody looked, because a devoted daughter signing for her father did not feel like a question.

Key takeaways