HL7 Resources

HL7 Data Types

HL7 data types define the kind of data that can be included in a field, and are used throughout the HL7 message structure. Examples would be a string, formatted text, timestamp, address, or coded element. Each data type may contain additional data types that are referenced as components or subcomponents. Complex data types use other data types to define the kind of data they can contain.

Certain data types cannot reference each other due to the nature of the components. For instance, a data type cannot reference data types that already reference multiple components, because there is no way to code the information at that level.

Below is a list of the HL7 data types:

DATA TYPE CATEGORY/ DATA TYPEDATA TYPE NAME
Alphanumeric 
STString
TXText data
FTFormatted text
Numerical 
CQComposite quantity with units
MOMoney
NMNumeric
SISequence ID
SNStructured numeric
Identifier 
IDCoded values for HL7 tables
ISCoded values for user-defined tables
HDHierarchic designator
EIEntity identifier
RPReference pointer
PLPerson location
PTProcessing type
Date/Time 
DTDate
TMTime
TSTime stamp
Code Values 
CECoded element
CFCoded element with formatted values
CKComposite ID with check digit
CNComposite ID number and name
CXExtended composite ID with check digit
XCNExtended composite ID number and name
Generic 
CMComposite
Demographics 
ADAddress
PNPerson name
TNTelephone number
XADExtended address
XPNExtended person name
XONExtended composite name and ID number for organizations
XTNExtended telecommunications number
Specialty/Chapter specific 
CDChannel definition
MAMultiplexed array
NANumeric array
EDEncapsulated data
CPComposite price
FCFinancial class
Extended Queries 
QSCQuery selection criteria
QIPQuery input parameter list
RCDRow column definition
Master Files 
DLNDriver’s license number
JCCJob code/class
VHVisiting hours
Medical Records/Info Mgmt 
PPNPerforming person time stamp
Time Series 
DRDate/time range
RIRepeat interval
SCVScheduling class value pair
TQTiming/quantity

Understanding components and subcomponents

A data type may reference one or more additional data types as components or subcomponents. For example, the CK (composite ID with check digit) data type can be broken down into four components, each referencing a specific data type. One of these components (HD) also references three other data types as subcomponents.

CK data type:

SEQDATA TYPECOMPONENT NAME
1NMID Number
2STCheck Digit
3IDCode Identifying the Check Digit Scheme Employed
4HDAssigning Authority

HD component:

SEQDATA TYPECOMPONENT NAME
1ISNamespace ID
2STUniversal ID
3IDUniversal ID Type

Want to learn more about HL7 and its Data Types? Enroll in Lyniate Academy’s HL7 training course now!

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