Clinical Terminology Service (CTS) is a shared service that provides an application programming interface to third-party terminology providers, such as HealthTerm™ and Health Language. It takes coded values from incoming HL7 messages and carries out the following transformations:

  • Code Normalization — The process of replacing a custom code identifier (code and coding system) with a standard code identifier from a recognized code set, such as LOINC or SNOMED.
  • Code Sensitivity — A lookup to determine the level of sensitivity associated with a coded term. For example, exposure to HIV.

Example 1

FieldSent to CTSAfter Normalization

After determining Sensitivity

PRB.3Problem IDZ21^suspected exposure to HIV^I10Z21^Asymptomatic human immunodeficiency virus [HIV] infection status^I10R
PRB.10Problem Classification Z20^exposure to human immunodeficiency virus^I10Z20^Contact with and (suspected) exposure to communicable diseases^I10
PRB.14Problem Life Cycle StatusG43.7^chronic migraine^I10G43.7^Chronic migraine without aura^I10

The confidentiality code R is inserted in the PRB.25 Security Confidentiality field, as CTS has identified PRB.3 as confidential.

Example 2

FieldSent to CTSAfter Normalization

After determining Sensitivity

PR1.3Procedure CodeV80.3^Screen for ear disease^I9Z13.5^Encounter for screening for eye and ear disorders^I10CM
PR1.15Associated Diagnosis Code90698^DTAP-HIB-IPV VACCINE, IM (90698)^C490698^Diphtheria, tetanus toxoids, acellular pertussis vaccine, haemophilus influenza Type B, and poliovirus vaccine, inactivated (DTaP - Hib - IPV), for intramuscular use^C4

Nothing is inserted in the ZPR1.1 Confidentiality Code field, as CTS has not identified either PR1.3 or PR1.15 as confidential.

Normalized Fields

The table below lists the fields that are normalized and enriched for confidentiality by CTS.

CTS normalizes this field
CTS sets the sensitivity level in this field


 FieldMessage TypeCTS sets the Confidentiality in this Field...
PRB.3Problem IDPPR 
PRB.10Problem ClassificationPPR 
PRB.14Problem Life Cycle StatusPPR 
 PRB.25Security ConfidentialityPPRIf PRB.3, PRB.10 or PRB.14 are normalized.
OBR.4Universal Service IdentifierORU 
OBR.26.1Parent Observation IdentifierORU 
OBX.3Observation IdentifierORU 
 ORC.28Confidentiality CodeORUIf OBR.4, OBR.26.1 or OBX.3 are normalized.
AL1.2Allergy TypeADT 
AL1.3Allergy Code Mnemonic DescriptionADT 
AL1.4Allergy SeverityADT 
DG1.3Diagnosis CodeADT 
 DG1.18Confidential IndicatorADTIf DG1.3 is normalized.
PR1.3 Procedure Code ADT 
PR1.15 Associated Diagnosis Code ADT 
 ZPR1.1Confidentiality CodeADTIf PR1.3 or PR1.15 are normalized.
IAM.2Allergen Type CodeADT 
IAM.3Allergen Code Mnemonic DescriptionADT 
IAM.4Allergy Severity CodeADT 
RXO.1.1Requested Give Code IdentifierOMP 
RXO.1.3Requested Give Code Name of Coding SystemOMP 
RXA.5.1Administered Code IdentifierRAS, VXU 
RXA.5.3Administered Code Name of Coding SystemRAS, VXU 
RXE.2.1Give Code IdentifierRDE 
RXE.2.3Give Code Name of Coding SystemRDE 
RXD.2.1Dispense Give Code IdentifierRDS 
RXD.2.3Dispense Give Code Name of Coding SystemRDS 
OBR.26.1Parent Result Parent Observation IdentifierORU 
RXR.1.1Route IdentifierOMP, RAS, RDE, RDS, VXU 
RXR.1.3Route Name of Coding SystemOMP, RAS, RDE, RDS, VXU 


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