As per ICH-GCP Guidelines, Serious Adverse Event (SAE) is

“Any untoward medical occurrence that at any dose:
– results in death,
– is life-threatening,
– requires inpatient hospitalization or prolongation of existing hospitalization,
– results in persistent or significant disability/incapacity,
– is a congenital anomaly/birth defect”


Adverse events may occurs during clinical investigations or trials, if it is medicinal product-related (Adverse Drug Reaction) then many reasons behind this occurrence like change in dose, population, needed monitoring, consent forms etc. This is very important when any reaction goes to its severe forms, threaten life or functions. In that case reactions should be reported to regulators.

Adverse Event and Serious Adverse Event Reporting Flow chart


Most of the guys thought that “serious” and “severe” both are same. This is a big confusion and misunderstanding between these two terms, I will show you how:

Term “severe” is used to describe the intensity or severity of the specific event or reaction (mild, moderate or severe); sometime it may be relatively minor medical significance (severe headache).

Terms “serious” is based on the patient/ event outcome or action criteria usually associated with the events that pose a threat to a patient’s life or functioning. As ICH-GCP E2A said “Seriousness serves as a guide for defining regulatory reporting obligations.”

A serious adverse event or reaction is any untoward medical occurrence that at any dose:

  • Results in death,
  • Is life-threatening,

IMPORTANT: As per definition of “serious”, the term “life-threatening” describe any event in which patient was at risk of death during event; it does not refer to an event which hypothetically might have caused death if it were more severe.

  • Requires inpatient hospitalisation or prolongation of existing hospitalisation,
  • Results in persistent or significant disability/incapacity, or
  • Is a congenital anomaly/birth defect.

Medical and scientific judgement should be exercised in deciding whether expedited reporting is appropriate in other situations, such as important medical events that may not be immediately life-threatening or result in death or hospitalisation but may jeopardise the patient or may require intervention to prevent one of the other outcomes listed in the definition above. These should also usually be considered serious.

Examples of such events are intensive treatment in an emergency room or at home for allergic bronchospasm; blood dyscrasias or convulsions that do not result in hospitalisation; or development of drug dependency or drug abuse.