HL7 Message Sets

HL7 messages are grouped by type or purpose into transaction sets. For example, a Patient Administration (ADT) message is used to transmit patient admittance, transfer, demographic and discharge information. The Patient Administration transaction set includes messages that transmit portions, instances, or updates of this data necessary to the participating healthcare system.

Control

Control defines the general rules that apply to all messages, including the form used to describe messages, encoding rules for converting abstract messages to string characters, programming procedures for exchanging messages, relationship with lower level protocols, common message segments, and the acknowledgment message that can be used as-is in multiple applications.

Patient Administration

The Patient Administration transaction set (HL7 Standard, chapter 3), one of the most commonly used, provides demographic and visit information about patients. The event is transmitted as an unsolicited update or as a response to a record-oriented query.

Order Entry

The Order Entry transaction set provides for the transmission of orders for materials or services, and information regarding orders, for specific patients or departments. Order Entry messages include components that specify quantity, timing, billing, start and end date, priority, and so on.

Query

The Query transaction set provides requests for specific information with either an immediate or deferred response, depending on the type of query. Newer versions of HL7 include many of the most common queries that are likely to occur in a hospital.

Financial Management

The Financial Management transaction set provides for the entry and manipulation of information pertaining to billing accounts, adjustments, payments, charges, insurance, and other related patient billing and A/R information.

Observation Reporting

The Observation Reporting message set provides for the transmission of structured patient-oriented clinical information. This includes clinical observations such as clinical laboratory results, the results of imaging studies (excluding images), EKG pulmonary function studies, vital signs, intake and output, measures of patient status and condition, severity and/or frequency of symptoms, drug allergies, diagnostic lists, physician and nursing history, physicals, progress notes, operative notes and so on. Message information is reported in text, numeric or categorical values.

Master File

A master file is a common reference file containing more or less permanent descriptive information about a principal subject. In the healthcare environment, some common master files are doctor, location, system user, patient status, patient type, lab test definition, exam code definition, and charge master files. The Master Files Notification messages support the distribution of changes to various master files between systems, by either providing changes to the files or making data available for review and possible inclusion.

Medical Records/Information Management

The Medical Document Management (MDM) transaction set provides for the transmission of new or updated documents. MDM messages may contain a description of the status of a document (for example, the document has been dictated and is awaiting transcription) or both the status description and the document itself. A medical document or record is a legal document that serves as an accurate and comprehensive account of healthcare services provided to a patient.

Scheduling

The Scheduling transaction set supports the communication of various events in relation to schedules, appointments, services and resources. A schedule controls the dates and times available for the performance of a service or the use of a resource. The scheduling set contains three basic types of messages:

• The Request transaction, used to request an appointment for services or the use of resources.

• The Query transaction, which actively solicits scheduling information between systems.

• The Unsolicited transaction, which passively gathers and provides scheduling information between systems.

Scheduling messages may also contain other supporting information, including the reason for the appointment, patient information, person initiating the appointment, and location.

Patient Referral

The Patient Referral transaction set provides for patient referral communications between separate healthcare related entities. This includes primary healthcare providers, hospitals, labs, specialists, government agencies, and other healthcare entities. The receiving entity may require billing information, test results, provider information, patient demographics and so forth, calling for multiple inquires and responses. For this reason, the referral set includes the referral, requests for information, and returned patient information.

Patient Care

The Patient Care transaction set supports the communication of problem-oriented records which include clinical problems, goals, and clinical pathway information. The problem in this case may be a diagnosis or other professional description of healthcare issues affecting a specific patient. Goals are objectives to be attained as the result of healthcare intervention applied to an individual. A pathway refers to a standardized plan of care by which progress toward an expected outcome is measured.

Laboratory Automation

The Laboratory Automation transaction set supports the communication of equipment information, including status, inventory, logs and service, test code settings, response, notification, and comment, as well as specimen status.

Application Management

The Application Management transaction set supports the transmission of application management information and application control-level requests.

Personnel Management

The Personnel Management transaction set supports the transmission of details regarding education, language, practitioner, and professional affiliations, as well as information on practitioner organization unit, and staff identification.