Serious adverse event

In drug development, serious adverse event (SAE) is defined as any untoward medical occurrence during a human drug trial that at any dose

1. Results in death
2. Is life-threatening
3. Requires inpatient hospitalization or causes prolongation of existing hospitalization
4. Results in persistent or significant disability/incapacity
5. May have caused a congenital anomaly/birth defect
6. Requires intervention to prevent permanent impairment or damage

The term "life-threatening" in the definition of "serious" refers to an event in which the patient was at risk of death at the time of the event; it does not refer to an event which hypothetically might have caused death if it were more severe. Adverse events are more broadly defined by international regulation as “Any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.”