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Office of Mental Health

Sentinel Events

What is a Sentinel Event?

A sentinel event is an unexpected occurrence involving death or serious physical or psychological injury, or the risk thereof. Serious injury specifically includes loss of limb or function. The phrase "or the risk thereof" includes any process variation for which a recurrence would carry a significant chance of a serious adverse outcome. Such events are called "sentinel" because they signal the need for immediate investigation and response. The terms "sentinel event" and "medical error" are not synonymous; not all sentinel events occur because of an error and not all errors result in sentinel events.

The Office of Mental Health (OMH) identifies the following incidents as Sentinel Events, when they occur in a 24 hour around the clock care setting: unanticipated death or major permanent loss of function unrelated to the natural course of the consumer's illness or underlying condition; suicide; sexual assault or abduction of a patient.

What is a Root Cause Analysis?

Root cause analysis (RCA) is a process for identifying the factors that underlie variation in performance, including the occurrence or possible occurrence of a sentinel event. A root cause analysis focuses primarily on systems and processes, not on individual performance. The analysis progresses from special causes* in clinical processes to common causes† in organizational processes and systems and identifies potential improvements in these processes or systems that would tend to decrease the likelihood of such events in the future or determines, after analysis, that no such improvement opportunities exist.

The following presentation is an introduction to what qualifies as a Sentinel Event and how to conduct a Root Cause Analysis in response to a Sentinel Event.

RCA Video Presentation

The following is a sample of a Root Cause Analysis in response to a Sentinel Event. This RCA is fictional and intended only for training purposes. This RCA is documented using a framework created by the Joint Commission. The Joint Commission has many resources related to RCA, including tools such as the framework used here, that can be found on their website

Root Cause Analysis SampleLeaving OMH site

* Special Cause is a factor that intermittently and unpredictably induces variation over and above what is inherent in the system. It often appears as an extreme point (such as a point beyond the control limits on a control chart) or some specific, identifiable pattern in data.

† Common Cause is a factor that results from variation inherent in the process or system. The risk of a common causes can be reduced by redesigning the process or system.

Comments or questions about the information on this page can be directed to the Bureau of Inspection and Certification (BIC).