Glasgow Coma Score

I believe that the modelling of the GCS needs updating.  Currently there are the following terms:

386554004 | Glasgow coma scale (assessment scale) |

68664003 | Glasgow coma testing and evaluation (procedure) |

3386557006 Glasgow coma scale finding (finding)

281395000 | Glasgow coma score eye opening subscore (observable entity) |

281397008 | Glasgow coma score verbal response subscore (observable entity) |

281396004 | Glasgow coma score motor response subscore (observable entity) |

There are even a whole series of coding for each score

248241002 | Glasgow coma score (observable entity) | score out of 14

444323003 | Modified Glasgow coma score (observable entity) | score out of 15  etc

However I cannot find a codes to code all the individual findings ?observations, qualifiers to the components below:

Eyes Opening

• Spontaneous  5054005 | Spontaneous (qualifier value) |

• To sound    247286002 | Finding of response to sound (finding) |  ?247297002 | Localization of sound source (observable entity) 

• To pressure --can find motor response only 299822001 | Motor response to deep glabella pressure present (finding) |

• None  ??260413007 | None (qualifier value) |

Verbal Response

• Orientated  426224004 | Oriented to person, time and place (finding) |

• Confused 40917007 | Clouded consciousness (finding) |

• Words 288612001 | Does use words (finding) |

• Sounds ?? 286256004 | Does make speech sounds (finding) | Is speech sounds intelligible? no grunt or groan sound codes except for breathing

• None  ? 260413007 | None (qualifier value) |

Motor Response

• Obey commands  248239003 | Response to commands (observable entity) |

• Localising in response to pain or sounds

• Normal flexion  in response to pain or sounds 123622004 | Normal flexion (finding) |

• Abnormal flexion   in response to pain or sounds 123623009 | Abnormal flexion (finding) |

• Extension  ?19212008 | Abnormal extension (finding) |

• None 260413007 | None (qualifier value) |

Steven, This is an area that I always find difficult as to the level of detail that could / should be modelled for assessment scales. The SNOMED editorial guide Staging and Scales doesn't address this in any great detail.  Agree that there are not all the clinical finding descriptions that relate to particular component scores of GCS.   Some help needed from the SNOMED authors and modellers here.

Andrew

I think the expectation has previously been that if you wanted to document the overall GCS score, then you should use:

EITHER

OR

OR

...which explicitly (in its modelling) states that it relates only to a vanilla 248241002 GCS and not to a modified 444323003 GCS (and so the option does not exist for recording a modified GCS as a finding precoordinated with the numeric value).

The option of recording a vanilla GCS as a finding precoordinated with the numeric value should, however, be noted to be suboptimal in many respects: firstly, the numeric value is not easy to extract and so charting the timetrend for the score will be challenging. Secondly, and for the same reason, there is no simple machine transform that could compute that the two FHIR Observation expressions:

1. Observation.code=248241002, Observation.value.valueQuantity=9

2. Observation.code=5999000

...are semantically equivalent. For that reason I think I would personally recommend either deprecation of that precoordinated Finding pattern with SI moving to inactivate that content, or SI adding the currently missing concrete domain modelling that would make exactly that kind of bidirectional transform and equivalence detection possible.

Correspondingly, if you also want to document the individual subscores that contributed to that total, you should use only:

Of course, this representation of the subscore requires that all readers will know that e.g. "GCS eye opening subscore =1" means "subject does not open eyes either spontaneously or in response to ANY stimulus".

An alternative encoding that I can imagine folk attempting, and which I think Stephen's query echoes, is therefore to replace the numeric values with human readable strings, along the lines of:

This approach is risky for a variety of reasons:

As in the case of 'spontaneous' above, for which two clinically interchangeable codes already exist, I think you'll rapidly find that more than one SNOMED code plausibly corresponds to the particular subscore 'values' you really want to capture and interoperate. And so, again, it will become challenging to reliably determine when two clinicians have said the same thing but in different ways, and so reliable interoperation fails.

You'll also have the problem of curating a 'map' between all possible adjectival values that clinicians may choose to select as a descriptive human readable representation of their underlying clinical assessment result, and the subscores in their abstracted numeric form as would be required if you're going to automatically compute the total GCS score from what the clinician's were persuaded or empowered to enter.

Finally, the 'none' option is especially problematic, as more generally is all negation. The following three are just some of the ways that a clinician might elect to record some aspect of a GCS assessment:

...but working out which are clinically equivalent, and what the actual subscore numeric value for each should be, is "challenging".

My recommendation would be to restrict clinicians (and clinical systems) to encoding GCS subscores only directly to the numeric. Onscreen data captured templates for use by clinicians can display more human readable prompts e.g. 'click here if moves limbs purposefully to remove painful stimulus of deep pressure to sternum' but that should be coded, and messaged, behind the scenes to:

..where the valueString can be different between clinical systems.