The Traffic Light Analogy: Patients aren’t cars #WILTW

This is the 162nd #WILTW

There are conflicting views on whether analogies between safety in the airline industry and medicine are reasonable. While aviation is applauded for its strong culture of training and disciplined team work, the fixed environment i.e. the same cockpit, with the same crew, in the same circumstances makes it difficult to compare with the unpredictable nature of clinical practice. The converse argument is that in healthcare we always find “an exception to the rule” so unified practice becomes impossible. It is likely this debate will continue to run, with no obvious winner, until medicine becomes a safe industry. Something it is currently, certainly not.

A safety initiative in road transport is a common feature of medical guidance: The Traffic Light.

The movement from green (clinical features which are not concerning and do not require intervention) to amber (may cause harm and require investigation) to red (must action immediately to avoid harm) is commonly used to highlight the key features of practice guidelines and risk in observation charts and scoring systems.

This approach implies there is a discrete and objective difference between the categories. While this may be true for vital signs (the movement from low to high heart rate for example) medicine rarely affords us anything which is black and white.

In a fantastic piece on the complexity of diagnosing paediatric sepsis Dr. Edward Snelson proposes the following:

Edward highlights that “Sepsis doesn’t appear, it develops“. There is a misconception that the point where sepsis began can always be identified. This is simply not the case and evidence supports this. A viral illness bringing you to hospital one day, may well still have been a viral illness regardless of whether you present to the hospital the next day with sepsis.

Given the evolving nature of many diseases is “tri-chotomisation”  a valid approach? In practice some clinical features may sit in one category, while some may sit in others.  Rather than green or amber, should we have brown? Trajectory of illness means it is far more meaningful, but infinitely less practical, to have a spectrum of colours rather than a traffic light.

Does the ease of use and face validity of the “Traffic light” trump the practical difficulty its implementation may produce?

With that particular challenge I leave you with Edward’s extremely relevant summary:

What have you learnt this week? #WILTW

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2 thoughts on “The Traffic Light Analogy: Patients aren’t cars #WILTW”

  1. In aviation I also suspect that it helps safety that the pilot and the passengers have the same fate; something that will never happen in medicine.

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