A Sentinel Event is defined by The Joint Commission (TJC) as any unanticipated event in a healthcare setting resulting in death or serious physical or psychological injury to a patient or patients, not related to the natural course of the patient's illness. Sentinel events specifically include loss of a limb or gross motor function, and any event for which a recurrence would carry a risk of a serious adverse outcome. Sentinel events are identified under TJC accreditation policies to help aid in root cause analysis and to assist in development of preventative measures. The Joint Commission tracks events in a database to ensure events are adequately analyzed and undesirable trends or decreases in performance are caught early and mitigated.
Specific Events requiring review
Sentinel events include "unexpected occurrences involving death or serious physical or psychological injury, or the risk thereof" and all of the following, even if the outcome was not death or major permanent loss of function:
- Infant abduction, or discharge to the wrong family.
- Unexpected death of a full-term infant.
- Severe neonatal jaundice (bilirubin over 30 milligrams/deciliter).
- Surgery on the wrong individual or wrong body part.
- Instrument or object left in a patient after surgery or another procedure.
- Rape in a continuous care setting.
- Suicide in a continuous care setting, or within 72 hours of discharge.
- Hemolytic transfusion reaction due to blood group incompatibilities. 
- Radiation therapy to the wrong body region or 25% above the planned dose.
In additional to the list above, The Joint Commission requires each accredited organization to define sentinel events for its own care system and put into place monitoring procedures to detect these events and a procedure for root cause analysis.
Actions and reporting
Participation is necessary by the leadership of TJC accredited healthcare organizations and by the persons closely involved in the systems under review. Causal factors are analyzed, focusing on systems and processes, not individual performance. Potential improvements, called an "action plan", are identified and implemented to decrease the likelihood of such events in the future. Each accredited organization is encouraged, but not required, to report any sentinel event to The Joint Commission. However, the organization is expected to prepare a root cause analysis and action plan within 45 calendar days of the event. In addition, healthcare organizations are required to notify the Food and Drug Administration (FDA) and device manufacturers within 10 days of a sentinel event caused by a medical device, according to the Safe Medical Device Act of 1990. Statistics of sentinel events are recorded and published by the FDA's MedWatch program.
Advantages of reporting sentinel events to The Joint Commission are:
- Adding to the database with dissemination to other health care facilities, preventing other adverse events.
- Consultation with The Joint Commission on implementing the root cause analysis and action plan.
- Association with national accrediting body reassures the public that all steps are being taken to prevent a recurrence.
Joint Commission actions
After review of the accredited facility's report on the sentinel event, The Joint Commission issues an Official Accreditation Decision Report that may modify the organization's current accreditation status, assign an appropriate "measure of success", or a require follow-up survey within six months. A healthcare facility that fails to complete a root cause analysis of the sentinel event and action plan within the time frame can be placed on "Accreditation Watch" by the Joint Commission, a status that can be publicly disclosed . The Joint Commission disseminates "sentinel event alerts" identifying specific sentinel events, their underlying causes, and steps to prevent recurrence. 
Further nursing research is ongoing at a number of 'magnet' hospitals in the United States, especially to reduce the number of patient falls that may lead to sentinel events.
- TJC: Sentinel Event Statistics - March 31, 2006
- A fatal tranfusion reaction must be reported within 7 days.
- Joint Commission on Accreditation of Healthcare Organizations: Sentinel Event Alerts