HL7

HL7  Health Level Seven (HL7) is a non-profit organization involved in the development of international healthcare informatics interoperability standards  Framework for exchange, integration, sharing, and retrieval of electronic health information  focuses on the clinical and administrative data domains  Key goal is syntactic and semantic interoperability

Pillars of Semantic Interoperability  A common Reference Information Model (RIM) spanning the entire clinical, administrative and financial healthcare universe  A well-defined and tool-supported process for deriving data exchange specifications ("messages") from the RIM  A formal and robust Data Type Specification upon which to ground the RIM  A formal methodology for binding concept- based terminologies to RIM attributes.

HL7 Standards  Conceptual Standards - HL7 RIM  Messaging Standards – HL7 v3.0  Document Standards – HL7 CDA  Application Standards – HL7 CCOW

HL7 RIM  HL7 Reference Information Model  Used in conceptual perspective  Follows object oriented developmental methodology  The fundamental model from which all v3 messages are derived is referred to as the Reference Information Model (RIM)  The RIM is a generic, abstract model that expresses the information content of all the areas of healthcare  Defines all the information from which the data content of HL7 messages are drawn

Core Concepts of RIM  Every happening is an Act Procedures, observations, medications, supply, registration, etc.  Acts are related through an ActRelationship composition, preconditions, revisions, support, etc.  Participation defines the context for an Act author, performer, subject, location, etc.  The participants are Roles patient, provider, practitioner, specimen, employee etc.  Roles are played by Entities persons, organizations, material, places, devices, etc.

HL7 RIM Backbone Classes A physical thing, group of physical things or an organization capable of participating in Acts, while in a role. A record of something that is being done, has been done, can be done, or is intended or requested to be done. A competency of the Entity playing the Role as identified, defined, guaranteed, or acknowledged by the Entity that Scopes the Role. An association between an Act and a Role with an Entity playing that Role. Each Entity (in a Role) involved in an Act in a certain way is linked to the act by one Participation-instance. Entity RoleParticipationAct A connection between two roles expressing a dependency between those roles. A directed association between a source act and a target act. Role Link Act Relationship n n

HL7 Messages  serves as a way for dissimilar applications and data architectures operating in a heterogeneous system environment to communicate with each other.

Components of HL7 Messages  Segments A logical grouping of data fields  Fields Characteristics  Position, Max Length, Type of Data, Optionality, Repetition, ID number, Name  Message Delimiters  Escape sequences in text

HL7 Message Sets  Control  Patient Administration  Order Entry  Query  Financial Management  Observation Reporting  Master File  Medical Records/Information Management  Scheduling  Patient Referral  Patient Care  Laboratory Automation  Application Management  Personnel Management

HL7 Message Example

HL7 CDA  HL7 Clinical Document Architecture  XML based markup standard  Encoding, structure and semantics of clinical documents for exchange  Contains any type of clinical content Discharge Summary Imaging Report Pathology Report etc.

HL7 CCOW  HL7 Clinical Context Object Workgroup  Designed to enable disparate applications to synchronize in real-time  Facilitates Context Management User Patient Clinical Encounter  Also facilitates Single Sign On  Used for both, client-server and web-based applications  CCOW server - Vault