<div title="Introduction">

Order sets can organize and structure complex health care plans into useful units of work for clinicians. An order within an order set can request any clinical activity including referrals (requests for encounters), acts, supplies, procedures and observations among others. Within the model presented herein, structured observations (observation events) and goal setting can also be supported as elements within the order set. The sharing of care protocols and regimes authored as phased order sets has a much broader audience for work on error reduction, standardization of care and quality improvement. Order sets in this context can be envisioned as action elements within a care plan, allowing a clinician to organize and request a step in a larger protocol. Definition of the structure and function of orders and order sets for integration into the the electronic medical record of a vendor compliant with the order set standard is a central issue in development of interoperable functionality necessary to shared guidelines. The application program interface to this medical record is assumed to be compliant with the HL7 clinical statements model consistent throughout HL7 guideline model developments.

This document proposes a multi-layered standard that supports the publication and maintenance of order set libraries, the sharing of order sets between collaborating institutions and entities, the structuring of order sets to support effective presentation and clinical use, and the importing and interoperation of order sets within advanced clinical guideline and care planning software. The proposal assumes that organizations employing this standard may deploy the depth of specification appropriate to their enterprise needs and the availability of vendor decision support software.

</div><div title="Assumptions">

Orders are requests and authorization for service from an ordering agent (user) to an action agent (a person, department, or system that will carry out the order). Orders are selected, submitted and processed by a clinician during an order (processing) session during which the clinician interacts with clinical information system (CIS) software designed for order processing. Order sets are one or more orders that are logically grouped, organizing and supporting a unit of clinical work or care planning.

In addition to the baseline specification provided by an order set, individual orders may require the clinician to supply additional detail information during an order processing session.

The functionality of the order interface, workflow and order processing software are a property of the CIS. This will be presumed to include features such as:

• Order presentation, modification and authentication

• Order duplication checking and alerting

• Medication order interaction checking and alerting

• Medication allergy checking and alerting

Within these assumptions, such CIS features may be enhanced with order set standards but provision of these functions are not the primary goal of this standard.

</div><div title="Relationship to RIM">

In the HL7 process of defining the relationship of published order sets to the HL7 RIM, a Domain Analysis Model (DAM) for order set publication was created. The Class diagram for the Order Set Publication DAM is included in the document. Compliant with HL7 policies, this DAM was then mapped directly to the RIM. From the mappings of the DAM to the RIM, an HL7 Domain Message Information Models (DIM or DMIM) was discussed and developed collaboratively with Structured Documents TC. A copy of the DMIM is included in this ballot. From the RIM mapping, a succinct Refined Message Information Model (RMIM) was developed to support creation of XML structures for messaging and in support of order set publication. The Order Set Document RMIM and a sample XML order set is included in this ballot.

HL7 documents are created with document headers, which hold the metadata about the document (document context), and document bodies, which hold the actual content to be communicated. This paradigm has been followed in the order set publication model. The header would include information about:

• who created the document, e.g. authors, authenticators

• what patient characteristics apply, e.g. age, gender, diseases and settings

• what provider characteristics apply, e.g. licensing, specialty

• a list of references cited in the document

The content section or body of the Order Set document will include one or more orders, references to other HL7 Order Sets and associated observations and goals. An HL7 Order Set, as a subset of an HL7 supported guideline, is a recommended and ordered set of acts within a Definition wrapper, prepared to support a complex set of actions when instantiated for a patient within an active care plan.

Each Order set may have one or more goals proposed, which are explained in more depth below.

In relation to function of the HL7 RIM, this means that an HL7 Order Set Document (in event mood) contains instances of HL7 Acts that are in the definitional mood but specify their case of expected use at the time of order set processing such as ObservationRequest, ObservationEvent and GoalAssertion, similar to what one would find in a master file of orders. On import to a clinical information system, these instances of Acts would be instantiated into the clinical ordering system as requests for tests or services, assertion of findings or setting of goals. From HL7's perspective, what happens inside the clinical ordering system is unknown. It is a "black box." However, during order processing for a patient, the status of these orders may be tracked externally in messages or CDA documents exported from the "black box" by the ordering application software.

In use case 3, a clinical decision support system may employ published order set items as actionable elements involved in improving guideline adherence. Order set documents will be instantiated into the clinical information system order master and order set items will be managed by the decision support software during order processing for effective use by the clinician.

</div><div title="Order Processing">

Master files (or Acts in Definition mood) are not actually changed as a clinician creates specific orders. Rather, the clinician creates new instances of Acts that are copied from the Acts in Definition mood. In other words, during an order session, a clinician processes the order set and confirms or denies the activation/commitment of items in the order set as the plan is instantiated for a patient. This action is called creating a care plan for the patient and produces instances of Acts in Intent mood. Usually, during an order session, instances of some or all of these Acts are also created in Order or Request mood and processed through an order management system. The order management system may elicit promises from a department or person who is then responsible for filling the order. These promises are instances of HL7 Acts with much of the same information about the acts, but are instantiated in Promise mood. When the order is actually filled, a new instance of the basic act is created in Event mood.

In summary, during order processing, each act in intent mood become instantiated as requests (orders), goals, and events as appropriate. These acts (requests, goals, and events) are linked with ActRelationships as they are created back to the elements of the (active) care plan. This order set processing, from the point of view of the HL7 RIM, consists of a generation of new act instances in various moods of the HL7 Business Cycle of Act Instances, all linked back to the original instances of the act in definition mood (order set) and intent mood (care plan). The order life cycle therefore consists of order instances tracked through one or more of the following mood transitions:

Definition > Intent > Request (order) > Promise > Event

Therefore, the post-condition of an Order Set Publishing use case comprises an order management and order set metadata layer that is the initial XML document published by the Order Set author and that is imported into a clinical system by a clinical system manager or provider. Although the entire document is in event mood, the individual order items within the document incorporate the definitional mood but the class names specify the expected use case of the Act at time of order processing.

</div><div title="Goal Setting">

Of critical importance in today's environment of evidence-based medicine is whether the application of an order set generated the desired outcomes, that is, met the desired goals for the patient. One or more goals for individual observations may be proposed with an order set. For example, if the goal were to walk 20 feet within 14 days, then, in HL7, this goal would be represented as an observation of walking ability, with mood of Goal, with a value of 20 feet and an effective date 14 days in the future. When the order set is processed by the clinician, the goal would be validated and activated within the care plan for the patient in question. Within the same care plan, observations would be ideally scheduled to measure progress against the goal. Goal variance may be calculated from the observation and the goal, e.g. patient walked 18 feet against a goal of 20 feet which allows one to derive a goal variance of (18ft minus 20ft) or (-2ft).

In summary, alignment of HL7 Published Order Sets with the HL7 RIM document and content structures are desirable to support the needs of practicing evidence-based medicine in a standards-based environment.

</div><div title="Importance of Observations">

The implementation of many evidence based guidelines requires the recording of key bits of information during the process of setting the care plan. The order set organizes and offers to the physician proposals for making key decisions and setting goals, but it must also assist and guide the recording of key observational data in a timely manner if is to assemble a complete action plan for the clinician at the time of order set deployment.

For example, the JCAHO core measure guideline for management of congestive heart failure (CHF)requires the physician to record the cardiac ejection fraction (EF) during the of hospitalization. Many hospital information systems (HIS) do not make the EF available as structured data. A desireable element of the admission order set for CHF would be a convenient method of recording of the last EF observation during the process of writing admitting orders. If the vendor HIS can employ such order elements, then the physician can comply with the guideline requirements during the admission order process.

Similar examples might include a recording of the current peak flow rate when admitting a patient with asthma, the office findings of oximetry for the patient with pneumonia in order to calculate the pneumonia severity scale during admission order writing or the patient pain score when writing postoperative orders following hip replacement. For these reasons there is a compelling reason that order sets should support the assertion of observations within the order set body.