Which of the following best defines a sentinel event?

• A. A minor equipment malfunction
• B. A routine safety check
• C. An unexpected occurrence involving death or serious physical or psychological injury, or the risk thereof, requiring immediate investigation
• D. An administrative error with no patient impact

Answer: (C)

Sentinel events are serious, unexpected patient safety incidents that result in death or serious physical or psychological injury, or present the risk thereof, and they require an immediate, formal investigation to determine root causes and prevent recurrence. The option captures that exact idea: an unexpected occurrence with the potential for death or serious harm that prompts swift investigation. Other scenarios don’t fit as sentinel events because a minor equipment issue, routine safety activity, or an administrative error with no patient impact either isn’t linked to serious harm or isn’t unexpected or requiring urgent review.