The Criteria, and Why They Are Narrow

Part of Consent and Vulnerable Populations: Emergency and Deferred Consent.

About 6 minutes. Free, in your language, no account needed.

Why this matters

Some of the most important questions in medicine can only be answered in circumstances where consent is impossible. Cardiac arrest, major trauma, stroke thrombolysis, status epilepticus, severe sepsis. The intervention must begin in minutes, the person is unconscious or in crisis, and there may be nobody available to ask.

Without a mechanism for research in these circumstances, these fields would have no evidence at all, and their patients would be treated on tradition indefinitely.

The mechanism exists and it is deliberately narrow, because it is the only place in research where a person is enrolled without anyone's agreement.

The conditions

Regulation (EU) No 536/2014 addresses clinical trials in emergency situations and permits inclusion without prior consent where, among other conditions: the urgency of the situation, caused by a sudden life-threatening or other sudden serious medical condition, makes it impossible to obtain prior informed consent from the subject and to supply prior information; there are scientific grounds to expect participation will produce a direct clinically relevant benefit resulting in a measurable health-related improvement alleviating the suffering or improving the health of the subject; it is not possible within the therapeutic window to supply prior information and obtain consent from the subject or their legally designated representative; the investigator certifies that they are not aware of objections previously expressed by the subject; the trial relates directly to the condition causing the impossibility of obtaining consent; and the trial poses minimal risk and burden compared with standard treatment.

The United States framework addresses emergency use and, separately in 21 CFR 50.24, planned emergency research with an exception from informed consent, which carries its own conditions including community consultation and public disclosure.

Why each condition exists

Urgency making consent impossible. Not inconvenient, not difficult. Impossible within the window in which the intervention must begin. A window of four hours is not an emergency exception; it is time to find a representative.

Prospect of direct benefit. The person is being enrolled without agreement, so the justification must include a realistic prospect of benefit to them.

Not possible to reach a representative in time. The representative route is tried first, and its unavailability is a fact about this situation rather than a general assumption about emergencies.

No known prior objection. If the person previously expressed a view, that view governs, and the investigator must certify awareness.

Relation to the condition. The research must concern the emergency that made consent impossible, which prevents the mechanism being used to enroll unconscious people in unrelated research.

Minimal risk and burden relative to standard treatment. The comparison is with what would happen anyway, not with nothing.

The condition most often stretched

Urgency.

A team designing a trial in a condition where treatment ideally begins quickly will describe the window as narrow, because the science favors early treatment and because a narrow window makes the exception available.

The honest question is different: within what period must treatment begin for the trial to be scientifically valid, and is that period genuinely too short to obtain consent from a representative who is frequently present in the emergency department.

Many trials described as requiring the emergency exception have windows of several hours, during which a family member is often at the bedside. That is not impossibility.

Where it is not available

Some jurisdictions do not permit enrollment without prior consent at all.

For a multi-country trial this is determinative rather than an inconvenience: the country cannot participate, and discovering it after site contracts are signed is an expensive error. It is one of the first questions to settle when designing any trial relying on this route.

In practice

A team designs a trial in acute stroke with a treatment window of four and a half hours.

The initial protocol proposes the emergency exception on the basis that stroke is an emergency and participants are frequently unable to consent.

The ethics review asks the sharper question: in a window of four and a half hours, with a family member present in the majority of cases, is it genuinely impossible to obtain consent from a representative.

The honest answer is no, in most cases.

The protocol is revised to a tiered approach: the participant consents where able; a representative consents where the participant cannot and one is available; and the emergency exception applies only where neither is possible within the window.

The trial proceeds. The exception is used in a minority of enrollments, which is the correct proportion, and each use is justified by that participant's circumstances rather than by the condition's general character.

What this looks like when it goes wrong

A trial in severe sepsis obtains approval for enrollment without prior consent, on the basis that participants are critically ill and unable to consent.

In practice, family members are present for most enrollments, often for hours.

The site enrolls under the exception routinely, because the approval permits it and because obtaining representative consent during a resuscitation is difficult and slow.

The approval was for circumstances in which consent is impossible. The site is using it in circumstances where consent is difficult.

At inspection the question is how many enrollments involved a representative who was present and could have been asked. Nobody recorded it, because the exception's application was treated as a property of the trial rather than as a determination about each participant.

Key takeaways