The Glasgow Coma Scale and the challenge of clinimetrics

D. Koch, S. Linn

Research output: Contribution to journalReview articlepeer-review


The Glasgow Coma Scale (GCS) is a clinimetic index that assesses the state of consciousness of victims of traumatic brain injury. It has become an integral part of the modern evaluation of head truma. The patient's ability to perform three tests of neurologic function (eye opening, motor response and verbal response) determines the total score. This index was developed in an 'ad hoc' manner, without clear standards for the evaluation of it's qualitative sensitivity, validity and consistency. In our review we used the innovative standards, which were developed by Feinstein AR, to evaluate this important ailment-oriented clinimetric index scale. The GCS demonstrates a conflict between two major goals: the goal of achieving a rating scale that is easily and reproducibly determined, and the goal of having a standardized scale with consistent validated results. The first goal was successfully achieved, based on evaluation of the principles of structure, choice of component variables, organization of output scale, statistical methods, psychometric properties, sensitivity-purpose, framework, format, face validity, content validity and the case of use of this clinimetric index. The GCS is a reliable consistent scale for evaluating responsiveness and for predicting coma outcome in patients with craniofacial injuries. However, the GCS is not a consistent measure for monitoring subtle changes in levels of consciousness or predicting outcome for individuals with scales in the middle range, especially because of paucity of componentts. In addition, there is a role for patient collaboration when using this clinimeric index, which is besed maninly on subjective observations. We suggest developing a transition coma index, to denote changes from the baseline condition. This approach eliminates the difficulty of using single-state clinimetric index for measuring change. A transition coma index should include a more specific classification of the level of consciousness, as well as auditory evoked potentials and brainstem reflexes as outcome predictors. In addition, there should be a better differentiation between normal and abnormal flexion, as well as between normal and abnormal eye opning (e.g. due to intact awareness, versus a vegetative state). Moreover, incorporation of an accurate categorization of diffuse head injury based on the result of the initial and a 24-hours follow-up CT scans as well as a comprehensive neurological examination, will allow identification of patients who may appear at low risk based on a GCS score.

Original languageEnglish
Pages (from-to)51-60
Number of pages10
JournalInternational Medical Journal
Issue number1
StatePublished - 2000
Externally publishedYes


  • Clinimetries
  • Epidemiology
  • Glasgow Coma Scale
  • Head trauma

ASJC Scopus subject areas

  • General Medicine


Dive into the research topics of 'The Glasgow Coma Scale and the challenge of clinimetrics'. Together they form a unique fingerprint.

Cite this