Waiving consent to receive research treatment in life or death situations may help patients in more ways than one, according to evidence from an international multicentre randomised controlled trial (RCT) of head injuries in unconscious patients.

It showed that waiving relatives’ consent allows patients to be treated sooner with potentially more benefit. It may also increase patient enrolment into trials, enabling the formal process of identifying effective new treatments for life threatening injuries.

Mean time to randomisation (and treatment) in the trial was significantly longer in those hospitals where consent was required compared with those where it was not (4.4 (SE 0.21) h v 3.2 (SE 0.16) h) and fewer patients were enrolled per month (1.5 (SE 0.24) v 2.0 (SE 0.29)).Though not proved, it seems reasonable that obtaining consent entailed some extra time. This was clinically important as treatment was needed within eight hours after the injury occurred and, ideally, as soon as possible to stand a chance of being effective.

The MRC CRASH trial is running in 160 hospitals in 40 countries with 4000 patients. Ethics committees in 78 hospitals have agreed to waive consent and the rest require relatives’ consent.

In emergencies patients may be unable to give consent themselves, but RCTs are essential in such situations to identify future treatments to prevent death and disability. Many ethics committees allow patients to take part in these trials without consent—those that do not risk delaying potentially lifesaving treatment, especially for neurological injuries, when time is crucial.