Sometimes a person with a chronic condition may deteriorate significantly before the problem is detected or treated. What may be readily apparent in hindsight may not have been so obvious at the time.

Requirements for the detection and intervention of a clinical deterioration

(1) need to look and observe

(2) need to receive key information (informed and aware)

(3) need to be cognitively aware (perceptive)

(4) need to interpret the information correctly

(5) need to act and follow through





not observing, masking

being informed

not being told essential information, including intentional withholding; given wrong information; false negative test


imperceptible change, inattentional blindness, unfamiliarity with what is normal for a patient, distraction


misdiagnosis (belief that something else explains the change, change not significant)

action and intervention

problem in hand-off or follow-up, decision to wait-and-see, breakdown in communication, therapeutic error



• The classic example of imperceptible change is the frog placed in a pot of water that is slowly heated.


Failure to detect deterioration must be distinguished from a sudden or catastrophic failure (acute or fulminant on chronic).


Hospital protocols with early warning scores is one method for early detection of clinical deterioration.

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