Error Vs Adverse Event

The hallmark report from the Institute of Medicine, USA, "To Err Is Human" released in the year 1999 estimated that up to 3.7 % of all hospitalizations suffer adverse events, and about half of them are likely due to errors (preventable adverse events).

It also quantified the actual damage by estimating that up to 98,000 hospitalized Americans die due to medical errors. To put this in context, this number is higher than total deaths due to motor vehicle accidents. Several other developed countries have similar national reports which have spurred call for action from different sectors of the society, but many are still unaware of the magnitude of the problem.

To better understand the issue, let me first introduce some necessary vocabulary in this post.

  Errors are failures of planned actions to be completed as intended, or use of wrong plans to achieve what is intended.

  Adverse events are injuries caused by medical intervention, as opposed to the health condition of the patient. A larger proportion of the adverse events are due to errors and in this case are better called preventable adverse event

  Negligence is a term used for adverse events that are purely due to low professional standards of healthcare professionals. Obviously these events may create some legal liability just because of their nature.

 Near Misses are serious errors that do not result in adverse events

 Not all adverse events are errors and not all errors result in adverse events (some are near misses). All cases of negligence are preventable adverse events. Most preventable adverse events are because of errors.

 The concept is beautifully explained by Dr. Robert M. Watcher in his writings. In an attempt to demonstrate the difference between an error and adverse event, a figure inspired by his explanation is as below: