Assessment Scales

There is work underway for a new R-MIM on scores and assessment scales. This page provides the material which will be used for the next ballot cycle. Patient Care has agreed to bring it to ballot as DSTU. So please feel free to support this initiative by providing additional input.

This paper will be organized according to the following three components:

1. Rationale for paying attention to assessment scales / scores / indexes as a separate topic
2. The HL7 v3 ballot material persé: use cases, storyboards, dynamic model, static R-MIM model.
3. Instructions for use to define assessment scale as Detailed Clinical Model, including the coding of it, and use it against the care statement / assessment scale R-MIM.

Contributors

Principal Contributor: Frank Oemig, Agfa HealthCare & HL7 Germany

Principal Contributor: William Goossen, MD

Principal Contributor: Kevin Coonan, MD

Principal Contributor: Sylvia Thun, MD, DIMDI

Principal Contributor: Rainer Röhrig, MD, University Hospital Giessen

Introduction

The most fundamental question is always how certain information in HL7 should be transmitted. In most cases, it is information that belongs to the category of "findings" or "observations". Therefore, in HL7 v2.x the OBX-Segment can be used. The code inOBX-2 explains what the observation is about. In HL7 V3 we will find some classes within the RIM and the appropriate domain models.

The so-called Score or assessment systems are findings. Score systems are so-called severity classification systems or point totals systems that pretend to make a quantitative statement on the severity and prognisis of a disease. Typically, scores combines individual values into a total which can be interpreted more easily. In the simplest case, it is just a single value or based on two individual values, in a complex case it can consist of several dozen values which are combined using a complex mathematical calculation.

This document tries to address two kinds of requirements. First, it should define which codes for the most important score and assessment systems must be used. On the other hand, it should explain how the information should be mapped to V3. (The basics may also be used - esp. regarding the definition of codes - to specify how this information can be transmitted with HL7 v2.x messages.

Scope

There are many score systems in use ([Wikipedia]). Many systems are in use on an international, national or just hospitalwide level. Others are just for scientific purposes.

Codes

For our communication the following information are of interest:

• Code (how to identify the data?)
• Codesystem (what is the originating catalog?) – LOINC, alternatively Snomed CT, if a licences is available
• name + description (short textual description)
• value (information)
• unit
• interpretation

In addition to this information for an individual score the underlying values used for calculation are of importance as well. But these are based on the same 6 points mentioned above.

Application Domains

The score systems can be assigned to specific domains. The following table lists the score systems (in alphabetic order) per domain with the assigned code (if available).

Score System	Description	Code	Codesystem
1. Intensive Care and Anasthesia
ABSI	Abbreviated burn severity index	n.v.
AIS	Abbreviated Injury System	273254002	Snomed CT
APACHE	Acute Physiology And Chronic Health Evaluation Score APACHE 2: APACHE 3:	9264-3 9265-0	LOINC
ASA	American Society of Anesthesiologists physical status classification	273270000 413347006	Snomed CT
CASUS	Cardiac Surgery Score	tbd
GCS	Glasgow Coma Scale (Beurteilung von Bewusstseinsstörungen bei Erwachsenen)	9269-2 35088-4 386560004	LOINC LOINC Snomed CT
HIS	Hannover Intensiv Score	tbd
HTI	Hospital Trauma Index	273525007	Snomed CT
ISS	Injury Severity Score	273533008	Snomed CT
KISS	Kombiniertes Intensiv Scoring System	tbd
LOD	Logistic Organ Dysfunction Score	58577001	Snomed CT
MOD	Multiple Organ Dysfunction Score
MOF	Multi-Organ-Failure-Score	tbd
MPI	Mannheimer Peritonitis Index	tbd
Ramsay	Ramsay sedation scale	281400004	Snomed CT
RASS	Richmond Agitation Sedation Scale	tbd
SAPS	Simplified Acute Physiology Score SAPS: 273811002 Snomed CT SAPS 2: 273812009 Snomed CT SAPS 3: n.v. ICD-10-GM
SOFA	Sepsis-related Organ Failure Assessment	tbd
TI	Trauma Index	273883005	Snomed CT
TISS	Therapeutic Intervention Scoring System: TISS-10 TISS-28 TISS-76	273878002 tbd	Snomed CT ICD-10-GM
TS	Trauma Score	273884004	Snomed CT
...
2. Patient Care
Barthel-Index (German)	Barthel Index, German version	273302005	Snomed CT ICD-10-GM
Barthel-Index (Dutch)	Barthel Index, Dutch version The Dutch modification makes use of a different scoring though the concept is the same		Snomed CT ICD-10-GM
Barthel-Index, expanded	cognitive function	ICD-10-GM
Braden Scale	Braden Scale	38227-5	LOINC
Braden Skin Ass. Pnl	Braden Skin Assessment Panel	38228-3	LOINC
BradenQ	Braden Scale for young children (<5 years)	tbd	LOINC
FIM	Functional Independence Measure	273469003 U50.-	Snomed CT ICD-10-GM
FRB	Frührehabilitations-Barthel-Index after Schönle	U52.- 273302005	ICD-10-GM Snomed CT
NEMS	Nine equivalents of nursing manpower use score	tbd
Norton	Norton score	278898009	Snomed CT
PPR	Pflegepersonal-Regelung	n.v.
Waterlow	Waterlow pressure sore risk score	278897004	Snomed CT
...
3. Psychiatry and Psychology
AMDP	Arbeitsgemeinschaft für Methodik und Dokumentation in der Psychiatrie	tbd
LFP	Lübecker Fähigkeitenprofil	n.v.
Melba	Merkmalprofile zur beruflichen Eingliederung von Behinderten	tbd
MMSE	Mini Mental State Examination	273617000	Snomed CT ICD-10-GM
...
4. Pediatry
Pediatric GCS	Pediatric Glasgow Coma Scale	n.v.
APGAR	after 1 minute after 5 minutes after 10 minutes	9272-6 9273-4 9271-8	LOINC
...
5. Mobility
	Tinetti-Test
	Timed “Up & Go
	Tandemstand
	Tandemgang
	Chair-Stand-Up
...
6. Cognition
DemTect
TFDD	Test zur Früherkennung von Demenzen mit Depressionsabgrenzung
	Clock Completion
...
7. Nutrition
MNA	Mini Nutritional Assessment(after Guigoz et.al.)
...
8. Psychology
APS	Acute Physiology Score
...
9. Geriatry
GDS	Geriatric Depression Scale	273481004 48544-1	Snomed CT LOINC
...
10. not otherwise classified
Bone density		385342005	Snomed CT
BMI	Body-Mass-Index measurement Body-Mass-Index	39156-5 41909-3	LOINC LOINC
BV	Bacterial vaginosis score	B96. N76.	ICD 10
FLACC	Face Legs Activity Cry Cinsolability Score	tbd
Gleason	Gleason Score	372278000	Snomed CT
HTI	Hospital Traum Index	273525007	Snomed CT
IADL	IADL (after Lawton and Brody)
LBK	Lübecker Fähigkeitenprofil
MPM	MPM 2 (0) MPM 2 (24, 48, 72) Mortality Prediction Model	273630004 273631000	Snomed CT Snomed CT
PHQ	Personal Health Questionnaire (Depression Score)
PSR	Periodontal Screening and Recording
VAS	visuell analog Scala	tbd
...

Of course, the details for the individual score systems are missing here. They are part of a separate document which is available in form of generated HTML files.

Code-Systems

The code systems are identified by their OIDs which are listed in the following table.

Codesystem	Descrption	Website	OID
LOINC	Logical Observation Identifiers Names and Codes	[www.loinc.org]	2.16.840.1.113883.6.1
ICD 10 GM 2005 icd10gm2005	ICD-Katalog (German modification 2005)	[www.dimdi.de]	1.2.276.0.76.5.304
ICD 10 GM 2006 icd10gm2006	ICD-Katalog (German modification 2006)	[www.dimdi.de]	1.2.276.0.76.5.311
ICD 10 GM 2007 icd10gm2007 icd10gm2007	ICD-Katalog (German modification 2007)	[www.dimdi.de]	1.2.276.0.76.5.318
ICD 10 GM 2008 icd10gm2008	ICD-Katalog (German modification 2008)	[www.dimdi.de]	1.2.276.0.76.5.330
ICD 10 GM 2009 icd10gm2009	ICD-Katalog (German modification 2009)	[www.dimdi.de]
Snomed CT	SNOMED CT is a concept-based, scientifically validated terminology that provides a unique and permanent concept identifier that can be included in multiple HL7 data types including CD and CE. The concepts are managed to avoid "semantic drift" so the meaning remains constant. If the concept is found to be ambiguous or the meaning changes, the concept is inactivated but still retained and the identifier is never reused. SNOMED CT's concepts are interrelated hierarchically and using description logic.	[www.snomed.org]	2.16.840.1.113883.6.96
OPS 2006 ops2006	Operationsschlüssel	[www.dimdi.de]	1.2.276.0.76.5.310
OPS 2007 ops2007	Operationsschlüssel	[www.dimdi.de]	1.2.276.0.76.5.317
OPS 2008 ops2008	Operationsschlüssel	[www.dimdi.de]	1.2.276.0.76.5.331
OPS 2009 ops2009	Operationsschlüssel	[www.dimdi.de]
Alpha-ID 2008 alphaid208	Alpha-Id 2008	[www.dimdi.de]	1.2.276.0.76.5.329
Alpha-ID 2009 alphaid209	Alpha-Id 2009	[www.dimdi.de]

Changes from Previous Release

There is currently no previous release. Therefore, this section will be filled next cycle.

Foundation

Assessment Scales – Scores Structure Overview

Given the interest in earlier versions of the Care Provision Ballot, further work has been undertaken on representing assessment scales, scores or indexes. The scientific testing of such instruments puts specific requirements and constraints on its use in HL7 v3 message structures in order to not only have a semantically equivalent data exchange, but also to keep the clinimetric characteristics of the instruments as a whole. The assessment scales, scoring systems or indexes are observations with specific characteristics. They can consist of severity classification systems or point totals systems that pretend to make a quantitative statement on the severity and prognosis of a disease or other aspect of human functioning. It is quite often an attempt to convert ‘soft’ observations into ‘hard’ data and evidence. Most of such instruments used in healthcare have been tested extensively on validity, reliability and usability. Many of such scoring instruments are used for decades and worldwide. Typically, assessment scales or scores combine the findings of individual values into a total score which can be interpreted more easily against a reference population. In the simplest case, it is just a single value or based on two individual values, in a complex case it can consist of several dozen values which are combined using a complex mathematical calculation or statistical technique.

This R-MIM tries to give guidelines on the representation in information models, in particular against the HL7 clinical statement pattern and the care statement R-MIM for care provision.

In addition to the information model, the appropriate use of terminology and consistency between the information model and the terminology model are crucial for safe exchange of such observations.

Clinical Statement extract

The R-MIM for the assessment scales / scores can be seen as an extract of Clinical and Care Statement Pattern, thus inheriting its characteristics. The R-MIM representation starts on top with the name and identification in the entry-point. For a detailed explanation of all attributes and vocabulary, the reader is referred to generic descriptions of the Reference Information Model, and to the walkthrough of the care statement D-MIM.

Score Observation

The R-MIM then starts with the score observation out of the choice box. As said above, the crucial attributes include:

• code: used to identify the variable and in which also the code system can be listed.
• text: attribute to allow the name and description of the assessment instrument
• value in which the actual score and where applicable the unit can be entered
• interpretationCode where the interpretation of the value can be explained via codes, often against a reference value.
• In the derivation code the total score for the assessment scale is recorded. In other words: derivation method is for example to add all values of the separate scores towards the total score.
• Effective time is the point in time on which the instrument is scored. In order to be valid and reliable, the scoreItems need to have (almost) the same time stamp. Such constraints posed by assessment instruments are important and expand beyond the mere semantic interoperability. For the receiver it is not only important to understand what the message content means, but also be ascertained that the data are collected based on the guidelines for the instrument.
• In the value of the score, which was created by adding the individual score items, is filled up. This is often a Coded Ordinal data type because it is mandatory to score and fill up all items to get a proper sum score. That is why Mandatory (1..1) component relations often exist for scoring instruments.
• Of course all relevant attributes can be applied as needed.

Component relationship to ScoreItem Observation

In principle, a score is based on specific observations, or other scores. From this point onwards a recursion starts based on the component relationship, allowing either including other score values or observations a score is based upon. Beneath the score Observation is the Observation (OBS) with the name Score item. Both the class Score and the class ScoreItem have classCode=OBS.

Derived from relationship to Care Statement CMET

The derivedFrom relation to care statement allows the user to describe any relevant information related to why a score item is scored this way. It allows to express any human thoughts as observations to go alongside with the score itself, or any circumstances as a procedure being carried out, or a specific encounter when it was measured. The relationship is to the choice box, allowing to make such statements on the level of the assessment instrument as a whole, or for an individual scoreItem.

Linkages to subject and provider roles

Several participations include different human actors, i.e. the patient, the observer, data enterer etc. They are linked to different CMETs providing the required details. The description and explanation of the CMETs is not part of this specification.

Score System Categories

The score systems can be divided into different categories: Those with arbitrary scores, those with discrete values and those with an unspecified number of values. Patient Classification Systems for workload are examples of the first one, the Barthel Index is an example of the second category, the BMI (Body Mass Index) an example for the third.

Arbitrary Scores

A scale is a set of linear values from a certain range. A reference range can be determined. In this case, an interpretation according to the conventional scheme is possible, i.e. a value is interpreted as "normal" if it is within the area - or at least close to one of its borders:

However, it should be noted here that an interpretation as too low is not necessarily combined with the abnormal flag. The flagging is somehow independed from the defined reference range.

Discrete Values (Scores)

Within this cetagroy, the "normal range" and the number of all possible values are identical. Therefore, the standard usage of reference ranges does not work. In principle, the whole range is devided into smaller parts each representing a specific interpretation:

So for example, the (German) Barthel Index allows for the values of 0 to 100 in steps of 5. The reference range, which can be specified, is within the same range, so that the available assessment opportunities (Abnormal flags) are not usable. The interpretation of a score is depending on the part of the reference range to which it belongs. Hence, the referenceRange relationship (one to many) to another OBS with the name ScoreRange.

For example:

The interpretation shows how the total score should be interpreted. For instance for the Dutch version of the Barthel index, this is 0-9 for seriously limited, 10-19 for moderately limited and 20 for independent.

As mentioned above, an assessment of the results by the conventional scheme of a reference range, where values outside are too high or too low, does not to apply. All values are falling into the range as defined by the score system. This range is - as explained above - to be divided into sections, which then can be evaluated/interpreted separately. Each score system is going to have its own (new) set of interpretation values. Each score system should get its own set of interpretation values which can be defined according to the following scheme. If the code values are coming from different code systems, then they must be included:

Eventually, some score systems may share the same interpretations. But this is up to individual examinations.

The following table is the interpretation for the German Barthel Index

Code system	Code	ValueFrom	ValueTo	Interpretation
ICD 10 GM 2007	U50.00	85 - 95	Leichte motorische Funktionseinschränkung
ICD 10 GM 2007	U50.10	60 - 75	Mittlere motorische Funktionseinschränkung
ICD 10 GM 2007	U50.20	40 - 55	Mittelschwere motorische Funktionseinschränkung
ICD 10 GM 2007	U50.30	20 - 35	Schwere motorische Funktionseinschränkung
ICD 10 GM 2007	U50.40	100 - 100	Keine oder geringe motorische Funktionseinschränkung
ICD 10 GM 2007	U50.50	0 - 15	Sehr schwere motorische Funktionseinschränkung

Storyboard

This D-MIM can be used in different circumstances. Right now, four different use cases are foreseen.

Assessment Scale Define

The D-MIM can be used in definition mood, so that it can convey information about the score system resp. assessment scale itself.

Assessment Scale Order

The primary codes, i.e. the ones on top level and not for the components, can be used to send a request for an observation using scores and assessments.

Assessment Scale Observation

The result of such an observation can be transmitted.

Assessment Scale Query

It should be possible to query for previous results as well.

Application Roles

According to the use case different combinations of application roles are applicable:

• informer - tracker
• placer - fulfiller
• query placer - query fulfiller

Trigger Events

The associated trigger events depend on the use case. This template an be used in messages and/or documents. Therefore, the events will vary.

Refined Message Information Models

HL7 V3 provides the "Clinical Statement Pattern". Here one can find the activity "Observation" with the necessary details. Facilitating this "basic structure", the pattern/template can be reused in other domains as well.

A_ObservationAssessmentScales-Scores (REPC_RM000125UV)

A score or assessment value is an observation. Therefore, as an entry point the observation act has been chosen. If the total score value is to be transferred only, they may use the Observation-Act directly (and exclusively).

But if the total score including all individual observations, the latter has to be assigned to the score as components. This assignement is done recursively so that a component can be a score itself. Within this recursion one can refer to a score or an observation which is used to calculate the total score. Therefore, the act relationship link is done from Score to ScoreChoice.

Both classes can be linked by participations to CMETs for performer, verifier, author etc. or to refer to a reference range.

Walkthrough

The walkthrough will be done in the following order:

• Score
• Score Item
• Act-Relationship component
• Participation author
• Participation unterzeichzner
• Participation verifier
• Participation performer
• Participation dataEnterer
• Participation subject
• Act-Relationship referenceRange
  • Score Range
• Act-Relationship derivedFrom
  • CMET A_CareStatement

Class Score

This act conveys information about the score itself and acts as a container (grouping) for the details to this score.

classCode := OBS

A score is an observation. Therefore the classCode is set to “OBS”.

moodCode <= ActMoodCompletionTrack

This value can come from ActMoodCompletionTrack and therefore allows to use in different business cycles. Normally, using "EVN" is foreseen. But "RQO" for requests or "DEF" for conveying information about itself is permitted as well.

Here we have to admit, that "DEF" is officially not allowed within clinical statement patterns. This is an action item for the next harmonization meeting.

id (Score-ID) := SET<II> [1..*]

Each Score is identified by a unique id. A value must be provided, esp. if the information is used in different phases of a business cycle.

code (score system) := CD CWE [1..1]

This is the primary value to identify the score system and therefore mandatory. The value may come from different code systems. The possible values can be found in the database.

derivationExpr (calculation method) := ST [0..1]

This optional field can be used to specify how the total score is calculated. In most cases to total score will be the sum of its components. But complex mathematical functions are possible as well. In some cases the calculation is a matter of copyright issues.

function	description	Example
direct value	Score only consists of a single value. This vlaue is just interpreted.	RASS Ramsay
sum	The different details are single values which are added into a total.	Barthel Apache II
mathematical calculation	The details are combined according to a mathematical functions.	BMI
combination	The values are combined somehow, e.g. by concatenation.	PPR
...

statusCode (Status) := CS CNE [1..1] <= ActStatus

In most cases the information is transmitted after calculation. Therefore, the statusCode will be "completed".

value (total Score Value) := ANY [0..1]

This field contains the value of the total score itself. Normally, it will be an integer or coded ordinal. But other datatypes like strings as for PPR ("A1S2") or real values for BMI are allowed as well.

interpretationCode (Interpretation) := SET<CE> CWE [0..*] <= ObservationInterpretation

This field contains the interpretationof the score value. The code comes from a value set which has been defined for this score system.

Class ScoreItem

Like the class Score this act conveys information about the component to a score.

classCode := OBS

This act is a placeholder for individual observations. Therefore the classCode is set to “OBS”.

moodCode <= ActMoodCompletionTrack

This value can come from ActMoodCompletionTrack and therefore allows to use in different business cycles. Normally, using "EVN" is foreseen.

id (Score-ID) := SET<II> [0..*]

Each component can be identified by a unique id. A value can be provided, esp. if the information is used in different phases of a business cycle.

code (score system) := CD CWE [1..1] <= ActCode

This is the primary value to identify the component of the score system and is therefore mandatory. The value may come from different code systems. The possible values can be found in the database.

statusCode (status) := CS CNE [1..1] <= ActStatus

In most cases the information is transmitted after calculation. Therefore, the statusCode will be "completed".

value (score value) := ANY [0..1]

This field contains the value of the score component.

interpretationCode (interpretation of the value) := SET<CE> CWE [0..*] <= ObservationInterpretation

This field contains the interpretation of the score component value. The code comes from a value set which has been defined for this component of the score system.

Act-Relationship component

This act relationship is used to link a score (as parent) to its components (as children). The use is optional.

typeCode := COMP

Diese Angabe verweist auf die Einzelinformationen, aus denen sich der Score-Wert zusammensetzt.

Participation performer

s. VHitG-Arztbrief

Participation author

Using this participation the information about the author is included.

author (Angaben zum Author) := [0..*]

Optional können die Score-Werte mit anderen Authorangaben versehen werden.

functionCode (function of the author) := CE CWE [1..1] <= ParticipationFunction

In der verpflichtenden Funktionsangabe wird angegeben, in welcher Funktion der Author an der Erstellung der Score-Werte mitgewirkt hat.

time (Zeitpunkt der Dokumentation) := TS [1..1]

Im verpflichtend anzugebenden time Attribut wird der Zeitpunkt der Dokumentation angegeben.

Participation Unterzeichner

Ähnlich dem Author können diverse Unterzeichner angefügt werden. Diese Participation ist in obiger Grafik übersichtshalber nicht enthalten.

Participation verifier

s. VHitG-Arztbrief

Participation dataEnterer

This participation is linked to the R_AssignedPerson CMET.

Participation subject

Using this participation information about the patient is conveyed. This participation is linked to the R_Patient CMET.

CMET Choice Box

The following CMETs are assigned to the previously listed participations:

• R_AssignedEntity [universal]
• R_Patient [universal]
• R_RelatedParty [universal]
• R_AssignedPerson [universal]

Act-Relationship referenceRange

Über diese (optionale) Beziehung wird der Referenzbereich für den Score-Wert festgelegt. Das ist der Bereich der Werte, in dem die meisten (aber nicht alle) Gesunden liegen sollten.

Mitunter gelten die Bereichsfestlegungen über Normalwerte nicht, da die gemessenen/errechneten Werte alle innerhalb des Normbereiches liegen, jedoch unterschiedlich interpretiert werden müssen. In diesem Fall findet die „Precondition“ Anwendung.

typeCode := REFV

Diese Angabe deklariert die Beziehung als Bereichsfestlegung.

seperatableInd := BL [0..1]

Diese Information gibt an, ob die Quell-Klasse (Score-Wert) auch ohne den Referenzbereich genutzt werden darf oder nicht.

class ScoreRange

In dieser Klasse werden die Normbereiche – evtl. mit Vorbedingungen – übermittelt.

classCode := OBS

Da es sich hier ebenfalls um eine Beobachtung handelt ist der classCode natürlich “OBS”.

moodCode := EVN.CRT

Die Einzelwerte als Grundlage des Score-Wertes sind ermittelt worden, d.h. sie liegen vor und werden deshalb im Event-Mood übermittelt.

negationInd := Verneinung BL [1..1] <= false

Die Normbereiche werden nicht verneint.

value (Bereichswert) := ANY CWE [1..1] =

In diesem Feld wird der Normwertbereich angegeben. Typischerweise wird er als Intervall kommuniziert. Es ist aber auch denkbar, dass hier eine Wertemenge angegeben wird, so dass der Datentyp SET<T> zum Einsatz kommt.

Act-Relationship derivedFrom

This act relationhip links the information for the score system and its components to "real" care information. Sometimes objective inormation which has been stated earlier can be reused within a score or at least to calculate the informatione needed within the score components from measured values. This generic relationship allows for inclusion of arbitrary information as needed.

typeCode := DRIV

The score (item) information is derived from care information.

Hierarchical Message Descriptions

tbd

Dynamic Model

This information model represents a generic template which can be used in messages and documents as well.

Open Issues

Description Parent: Care Structures Event Statement (REPC_RM000100UV)