Serious adverse event (SAE)

Any unfavourable occurrence in a trial participant that has a major impact on their health.

All SAEs occurring during a trial must be documented in clinical study reports and whether they are considered related to participation in the trial. Independent investigations are carried out to determine whether the SAE was potentially related to the trial intervention or was a random occurrence.

Suspected unexpected serious adverse reactions (SUSARs) are those considered likely to have been caused by the study intervention.

Safety monitoring and reporting for clinical trials in Europe (EMA, 2021)

Guidance for industry and investigators safety reporting requirements for INDs and BA/BE studies (FDA, 2012)