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Definitions abound in the medical error and patient safety literature, with subtle and not-so-subtle variations in the meanings of important terms. We have tried to adopt the most straightforward terminology, with definitions that enjoy the widest use.


Latent Error (or Latent Condition):
The terms "active" and "latent" as applied to errors were coined by James Reason.(1,2) Latent errors (or latent conditions) refer to less apparent failures of organization or design that contributed to the occurrence of errors or allowed them to cause harm to patients. For instance, whereas the active failure in a particular adverse event may have been a mistake in programming an intravenous pump, a latent error might be that the institution uses multiple different types of infusion pumps, making programming errors more likely. Thus, latent errors are quite literally "accidents waiting to happen."

Latent errors are sometimes referred to as errors at the "blunt end," referring to the many layers of the health care system that affect the person "holding" the scalpel. Active failures, in contrast, are sometimes referred to as errors at the “sharp end,” or the personnel and parts of the health care system in direct contact with patients.

1. Reason JT. Human Error. New York, NY: Cambridge University Press; 1990.
[ go to PSNet listing ]

2. Reason J. Human error: models and management. BMJ. 2000;320:768-770.
[ go to PubMed ]

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