Assessment Scale Results

3.3

An assessment scale is a collection of observations that together yield a summary evaluation of a particular condition. Examples include the Braden Scale (used for assessing pressure ulcer risk), APACHE Score (used for estimating mortality in critically ill patients), Mini-Mental Status Exam (used to assess cognitive function), APGAR Score (used to assess the health of a newborn), and Glasgow Coma Scale (used for assessment of coma and impaired consciousness.)

Assessment scales share certain features, which are described here as part of a recommended pattern:

1. Assessment scales have one or more component observations that can be taken in aggregate to provide an overall score (e.g. [ 248241002 | Glasgow Coma score ]).
2. Assessment scale component observations can be represented as a question and answer (e.g. [ 248240001 | Motor response ] = "3") or as a finding (e.g. [ 85157005 | Decorticate posture ]). Either or both of these representations may need to be communicated, depending on the use case.

The following Figure shows a sample Glasgow Coma Scale and result. A score is given for each of three types of neurological responses. A Coma Score of 13 or higher indicates a mild brain injury, 9 to 12 is a moderate injury and 8 or less a severe brain injury.

Glasgow Coma Scale

Glasgow Coma Scale	Value	Score
Eye Opening
spontaneous	4
to speech	3
to pain	2	2
no response	1
Motor Response
obeys verbal command	6
localizes pain	5
flexion-withdrawal	4
flexion-abnormal	3	3
extension	2
no response	1
Verbal Response
oriented and converses	5
disoriented and converses	4
inappropriate words	3
incomprehensible sounds	2	2
no response	1
Glasgow Coma Score	7

3.3.1

<observation classCode="OBS" moodCode="EVN"> 
  <code code="248241002|Glasgow coma score" codeSystem="2.16.840.1.113883.6.96">
    <displayName value="Glasgow coma score"/> 
  </code>
  <derivationExpr/> 
  <value xsi:type="INT" value="7"/> 
  <actRelationship typeCode="DRIV"> 
    <observation classCode="OBS" moodCode="EVN"> 
      <code code="288598006|verbal response|" codeSystem="2.16.840.1.113883.6.96">
        <displayName value="verbal response"/> 
      </code>
      <value xsi:type="INT" value="2"/> 
    </observation> 
  </actRelationship> 
  <actRelationship typeCode="DRIV"> 
    <observation classCode="OBS" moodCode="EVN"> 
      <code code="248240001|Motor Response|" codeSystem="2.16.840.1.113883.6.96"gt;
        <displayName value="Motor Response"/> 
	  </code>
      <value xsi:type="INT" value="3"/> 
      <actRelationship typeCode="XFRM"> 
        <observation classCode="OBS" moodCode="EVN"> 
          <code code="ASSERTION" codeSystem="2.16.840.1.113883.5.4"/>
          <value xsi:type="CD" code="85157005|Decorticate posture|" codeSystem="2.16.840.1.113883.6.96">
            <displayName value="Decorticate posture"/>
          </value>
        </observation> 
      </actRelationship> 
    </observation> 
  </actRelationship> 
</observation> 

The aggregate observation is modeled as a component of the assessment procedure. The <derivationExpr> can contain a formal language expression specifying how the value is computed. Component observations are nested under the aggregate observation, linked with a "DRIV" (is derived from) relationship. Where a component observation needs to be communicated in different formats, each format is a discrete observation, linked by a "XFRM" relationship.