4 . Order Entry

Chapter Chair/Editor:

Clement J. McDonald, MD Regenstrief Institute and Indiana University School of Medicine

Chapter Chair/Editor:

Hans Buitendijk Siemens Medical Solutions Health Services

Chapter Chair/Editor:

Gunther Schadow The Regenstrief Institute for Health Care

Chapter Chair/Editor:

Helen Stevens McKesson Information Solutions

Chapter Chair/Editor:

Austin Kreisler McKesson Information Solutions

Editor

Scott Robertson Kaiser Permanente

4.1 CHAPTER 4 CONTENTS

4.2 PURPOSE

The Order Entry transaction set provides for the transmission of orders or information about orders between applications that capture the order, by those that fulfill the order, and other applications as needed. An order is a request for material or services, usually for a specific patient. These services include medications from the pharmacy, clinical observations (e.g., vitals, I&Os) from the nursing service, tests in the laboratory, food from dietary, films from radiology, linens from housekeeping, supplies from central supply, an order to give a medication (as opposed to delivering it to the ward), etc.

Most orders are associated with a particular patient. However, the Standard also allows a department to order from another ancillary department without regard to a patient (e.g., floor stock), as well as orders originating in an ancillary department (i.e., any application may be the placer of an order or the filler of an order).

We refer to the person or entity who places the order as the placer. We refer to the person or entity that carries out the order as the filler (producer in ASTM terminology). In the case where the person or entity that carries out the order also requests the order, this person or entity is referred to as the filler and placer of the order. The filler may also request another application to assign a filler or placer order number.

This chapter defines the transactions at the seventh level, i.e., the abstract messages. Various schemes may be used to generate the actual characters that make up the messages according to the communications environment. The HL7 Encoding Rules will be used where there is not a complete Presentation Layer. This is described in Chapter 2, Section 2.6, "Message construction rules." The examples included in this chapter were constructed according to the HL7 Encoding Rules.

4.2.1 Preface (organization of this chapter)

This chapter has been organized into six major sections, General, Diet, Supply, Pharmacy, Vaccine and Transfusion Services. Each section contains the trigger events, message definitions, segments and examples for the specific type of order messages. Each section about a type of order is organized into background and overview, message structure, and message segments (that are specific to the order class in question). Special discussions of the use of fields, segments or messages, and examples are included. Segments are introduced in order of occurrence in a message. A list of allowable values for a field is included in the body of the text, along with the field definition for easier reference.

Section 4.3 refers the reader to Chapter 2 for an outline of the Quantity Timing (TQ) Data Type Definition.

Sections 4.4 to 4.6 'General' includes the triggers and segments for the clinical observations and diagnostic studies as well as the triggers and message segments that are common to all of the order entry messages. Orders for laboratory tests, bedside monitoring, diagnostic imaging, electrocardiograms, vital signs, etc., are subsumed under this order message set.

Sections 4.7 to 4.9 'Diet' includes all of the usual diet specifications including snacks and guest trays

Sections 4.10 to 4.12 'Supply' includes order messages for both Stock and No-stock orders. Supply orders are different in that they often are not patient-centered (e.g., requests to stock the ward supply room).

Sections 4.13 to 4.16 'Pharmacy / Treatment' includes all pharmacy and treatment related order messages. These sections additionally include triggers related to the dispensing, giving and administration of orders. In the development of the treatment order transaction set, the focus has been on medication treatments, but the same transaction set works well for total parenteral nutrition (TPN). There is hope that it is also sufficient for other kinds of treatment orders, such as those performed by the nursing service. But it has not yet been exercised in that context and may well need further development.

Sections 4.17 to 4.19 'Vaccine' includes triggers and segments specific to vaccination order messages. These sections also include RXA definitions specific to vaccination messages.

Sections 4.20 to 4.22 _Transfusion Service (Blood Bank)_ includes triggers and segments specific to transfusion service messages.

4.2.2 Glossary

4.2.2.0

4.2.2.1 Filler:

The application responding to, i.e., performing, a request for services (orders) or producing an observation. The filler can also originate requests for services (new orders), add additional services to existing orders, replace existing orders, put an order on hold, discontinue an order, release a held order, or cancel existing orders

4.2.2.2 Observation segment:

An OBX segment defined in Chapter 7.

4.2.2.3 Order:

A request for a service from one application to a second application. The second application may in some cases be the same; i.e., an application is allowed to place orders with itself.

4.2.2.4 Order detail segment:

One of several segments that can carry order information. Examples are OBR and RXO. Future ancillary-specific segments may be defined in subsequent releases of the Standard if they become necessary.

4.2.2.5 Placer:

The application or individual originating a request for services (order).

4.2.2.6 Placer order group:

A list of associated orders coming from a single location regarding a single patient.

4.3 QUANTITY/TIMING (TQ) DATA TYPE DEFINITION

Note: With version 2.5, the definition and narrative for the TQ _ Quantity/Timing data type has been moved to Chapter 2, Section 2.A.81. This section retained in v2.5 to maintain consistent section numbering for reference from other chapters.

4.4 GENERAL TRIGGER EVENTS & MESSAGE DEFINITIONS

This section includes trigger events and message definitions that are general to all orders in addition to the Observation and Diagnostic Study.

4.4.1 ORM - general order message (event O01)

Left for backward compatibility only. It is recommended that the trigger events OMG, OML, OMD, OMS, OMN, OMI, and OMP be used instead when communicating orders and order related events.

The function of this message is to initiate the transmission of information about an order. This includes placing new orders, cancellation of existing orders, discontinuation, holding, etc. ORM messages can originate also with a placer, filler, or an interested third party.

The trigger event for this message is any change to an order. Such changes include submission of new orders, cancellations, updates, patient and non-patient specific orders, etc.

The CTD segment in this trigger is used to transmit temporary patient contact details specific to this order.

4.4.1.1 ORM use notes

1. The abstract message syntax for some order segments vary slightly. Please refer to the appropriate sections for specific examples: for supply orders (RQ), see Section 4.10 "Supply Trigger Events & Messages" for pharmacy, see Section 4.13 "Pharmacy/Treatment Trigger Events & Messages"; and for dietary orders, see Section 4.7, "Diet Trigger Events & Message Definitions".

2. The segment named "Order Detail Segment" represents whichever of these order detail segment(s) is appropriate to the message, currently OBR, RQD, RQ1, RXO, ODS, ODT.

3. The NTE segment(s) can be included in the ORM message in four places; in each place the NTE refers to the segment which it follows. In particular, the NTEs following the MSH refer only to the message header, the NTEs following the order detail segment apply to the service defined by that ORC and order detail segment.

4. The PID segment is required if and only if new orders are being entered and they are related to a particular patient. For nonpatient-related orders the PID segment is never included.

5. The optional PV1 segment is present mainly to permit transmission of patient visit information such as current location with an order.

6. The order detail segments are not required when a simple control message is being sent. For example, a hold message (ORC-1-order control = HD) does not require that an order segment follow it.

7. ORC-1-order control is critical to the operation of both ORM and ORR messages. For example, to request cancellation of an order, one would transmit a CA in ORC-1-order control of the appropriate ORC. (See the definition of ORC-1-order control.)

8. A method to inquire for order status in the display format is provided in Chapter 2, and uses the record format provided in Chapter 7.

9. Each order message that defines any type of new order (ORC-1-order control = NW, CH, RO, or SN) requires an ORC/OBR pair to define each order to the receiving application. This also applies to any other types of orders, with the OBR being replaced by the appropriate order detail segment, as defined below. Thus two consecutive ORCs could occur if a cancel order request (needing only the order numbers) were followed by a second cancel order request. Many other examples are possible.

10. The insurance segments (IN1, IN2, and GT1) are typically used for external fillers, e.g., reference labs, where formal ADT transactions are overly complex or not needed.

4.4.2 ORR - general order response message response to any ORM (event O02)

Left for backward compatibility only. It is recommended that the trigger events ORG, ORL, ORD, ORS, ORN, ORI, and ORP be used instead when communicating orders and order related events.

The function of this message is to respond to an ORM message. An ORR message is the application acknowledgment to an ORM message. See Chapter 2 for a description of the acknowledgment paradigm.

In ORR the PID and ORC segments are optional, particularly in case of an error response. However, ORC segments are always required in ORR when an order detail segment is present. For example, a response ORR might include only the MSH and MSA, but if a RQ1 is present, it must be preceded by an ORC.

The function (e.g., cancel, new order) of both ORM and ORR messages is determined by the value in ORC-1-order control. (See the table of order control values for a complete list.)

Note: ORRs for supply, pharmacy, and dietary orders all have slightly different message syntax; refer to the appropriate sections as detailed in Section 4.4.1.1, ORM use notes, for exact details.

4.4.3 OSQ/OSR- query response for order status (event Q06)

OSR^Q06^OSR_Q06	Order Status Response	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
MSA	Message Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
[ { SFT } ]	Software		2	DB
[ { NTE } ]	Notes and Comments (for Header)		2	DB
QRD	Query Definition		2	DB
[ QRF ]	Query Filter		2	DB
[	--- RESPONSE begin
[	--- PATIENT begin
PID	Patient Identification		3	DB
[ { NTE } ]	Notes and Comments (for Patient ID)		2	DB
]	--- PATIENT end
{	--- ORDER begin
ORC	Common Order		4	DB
[{	--- TIMING begin
TQ1	Timing/Quantity		4	DB
[ { TQ2 } ]	Timing/Quantity Order Sequence		4	DB
}]	--- TIMING end
< OBR |	[Order Detail Segment] OBR, etc.		4	DB
RQD |
RQ1 |
RXO |
ODS |
ODT >
[ { NTE } ]	Notes and Comments (for Detail)		2	DB
[ { CTI } ]	Clinical Trial Identification		7	DB
}	--- ORDER end
]	--- RESPONSE end
[ DSC ]	Continuation Pointer		2	DB

4.4.3.1 Query usage notes

The QRD and QRF segments are defined in Chapter 2, Section 2.15, "Message Control Segments."

The subject filters contained in the QRD and QRF segments describe the kind of information that is required to satisfy the request. They are defined by local agreement between the inquiring system and the ancillary system. See the Implementation Guide for detailed examples of the use of query filter fields.

The Set ID fields in the various segments (including PID) are used to count the number of segments of one kind transmitted at one level of the hierarchy.

The Query Result Level field of the QRD determines the amount of data requested. See Chapter 5, Section 5.10.5.3, "QRD - original style query definition segment."

The OSQ message is a record-oriented query that has the structure as the regular QRY message. OSQ is included here for the convenience of implementers.

4.4.4 OMG - general clinical order message (event O19)

The function of this message is to initiate the transmission of information about a general clinical order that uses the OBR segment. Messages using the ORM message with the OBR segment are supported for backward compatibility. This includes placing new orders, cancellation of existing orders, discontinuation, holding, etc. OMG messages can originate also with a placer, filler, or an interested third party.

The trigger event for this message is any change to a general clinical order. Such changes include submission of new orders, cancellations, updates, patient and non-patient-specific orders, etc.

This trigger includes segments identified as being for 'previous results'. These segments allow the sending system to include demographic and/or result information from previous result reports when they are related to the current order.

For example:

• Diagnostic laboratories referring tests to another lab for either confirmation of results (HIV, etc.) or due to not being equipped to do the tests (genetic testing, etc.).

• Diagnostic laboratories sending test results to Knowledge Bases for the automated generation of diagnostic comments for inclusion into the lab report.

The CTD segment in this trigger is used to transmit temporary patient contact details specific to this order.

The function of this message is to respond to an OMG message. An ORG message is the application acknowledgment to an OMG message. See Chapter 2 for a description of the acknowledgment paradigm.

In ORG the PID and ORC segments are optional, particularly in case of an error response. However, ORC segments are always required in ORG when the OBR is present. For example, a response ORG might include only the MSH and MSA.

The function (e.g., cancel, new order) of both OMG and ORG messages is determined by the value in ORC-1-order control. (See the table of order control values for a complete list.)

The following message structure may be used for the communication of laboratory and other order messages and must be used for lab automation messages where it is required that the Specimen/Container information is within the ORC/OBR segment group. While the ORM message with the OBR segment can be used for backwards compatibility for general lab messages, only the OML message should be used to take advantage of the specimen and container extensions required in laboratory automation.

The trigger event for this message is any change to a laboratory order. Such changes include submission of new orders, cancellations, updates, etc. OML messages can originate also with a placer, filler, or an interested third party.

Note: The additional patient information (the segments PID, PD1, PV1, PV2, etc, which are sent after the OBR with the current order (indicated below with words "previous result"), could have been transferred with the previous result, because the patient demographics related to the previous result can differ from the demographics related to the current order. The current intent is to only allow references to the same patient as in the header PID.

The SAC segments included in the message allow the transfer of, e.g.: a laboratory order with multiple containers and multiple test orders related to each container, or laboratory orders with test order requiring multiple containers.

Refer to Chapter 13 Laboratory Automation for examples of usage, particularly to clarify the use of two references to SAC segments in this one message.

The CTD segment in this trigger is used to transmit temporary patient contact details specific to this order.

In relationship to triggers O21, O33, and O35, this message/trigger (O21) should be used where an order with multiple samples and optionally multiple containers per order item are to be communicated.

The function of this message is to respond to an OML message. An ORL message is the application acknowledgment to an OML message. See Chapter 2 for a description of the acknowledgment paradigm.

The trigger event for this message is any change to a laboratory order. Such changes include submission of new orders, cancellations, updates, etc where multiple orders are associated with a single sample which may be carried in multiple containers. OML messages can originate also with a placer, filler, or an interested third party.

This allows for a Specimen-centric message with multiple orders per specimen grouped by the specimen.

The following message structure may be used for the communication of laboratory and other order messages and must be used for lab automation messages where the message requires Specimen/container information to group a number of orders. While the ORM message with the OBR segment can be used for backwards compatibility for general lab messages, only the OML message should be used to take advantage of the specimen and container extensions required in laboratory automation.

In relationship to triggers O21, O33, and O35, this message/trigger (O33) should be used where an a specimen, with optional multiple containers, may have multiple orders are to be communicated.

The function of this message is to respond to an OML message where the original trigger event produced an OML with the Specimen Group segment above the ORC. An ORL message is the application acknowledgment to an OML message. See Chapter 2 for a description of the acknowledgment paradigm.

The trigger event for this message is any change to a laboratory order. Such changes include submission of new orders, cancellations, updates, etc where multiple orders are associated with a single sample which may be carried in multiple containers. OML messages can originate also with a placer, filler, or an interested third party.

This allows for a Specimen-centric message with multiple orders per specimen grouped by the specimen.

The following message structure may be used for the communication of laboratory and other order messages and must be used for lab automation messages where the message requires Specimen/container information to group a number of orders. While the ORM message with the OBR segment can be used for backwards compatibility for general lab messages, only the OML message should be used to take advantage of the specimen and container extensions required in laboratory automation.

In relationship to triggers O21, O33, and O35, this message/trigger (O35) should be used for laboratory orders where there is 1 or more Specimens with 1 to many containers each container may have 1 to many orders with previous result(s) per container.

The function of this message is to respond to an OML message where the original trigger event produced an OML with the Specimen Group segment above the ORC. An ORL message is the application acknowledgment to an OML message. See Chapter 2 for a description of the acknowledgment paradigm.

This message is used in communication between the information systems involved in the fulfillment of the request directed to the imaging department, such as a Radiology Information System (RIS) and a Picture Archiving and Communication System (PACS). For the purpose of the following discussion these systems will be identified as Imaging Department Information Systems (IDIS). Information contained in the Imaging Procedure Control (IPC) segment allows multiple IDIS to share the context of Imaging Studies (collections of images acquired, processed, stored, and interpreted) in Image Management tasks.

The order for the imaging service is communicated between the Order Placer (such as an Order Entry system) and the Order Filler (such as an RIS). In the imaging department environment, the Order Filler also identifies the set of procedures (studies) and sub-procedures (procedure steps) that have to be performed in the process of fulfilling the order. Each sub-procedure is performed using a single device (station). The Order Filler identifies the type of device and either a specific device or group of devices (for example, by geographic location) one of which is to be used in performing the procedure step. Thus, the system performs an aspect of workflow management in the department.

Another information system in the department may be managing storage and distribution of the images within the department as well as providing them to the enterprise. This system will have to operate within the same context as the system managing the workflow. This context includes identifiers, content of the order, and details of procedures and procedure steps that have to be performed to fulfill that particular order.

It is expected that the OMI message will typically be used in communication between IDIS as depicted in figure 4-1.

Figure 4-1. Use of OMI message

The function of this message is to respond to an OMI message. An ORI message is the application acknowledgment to an OMI message. See Chapter 2 for a description of the acknowledgment paradigm.

The following segments (ORC and BLG) are common to many order messages.

4.5.1 ORC - Common Order Segment

The Common Order segment (ORC) is used to transmit fields that are common to all orders (all types of services that are requested). The ORC segment is required in the Order (ORM) message. ORC is mandatory in Order Acknowledgment (ORR) messages if an order detail segment is present, but is not required otherwise.

If details are needed for a particular type of order segment (e.g., Pharmacy, Dietary), the ORC must precede any order detail segment (e.g., RXO, ODS). In some cases, the ORC may be as simple as the string ORC|OK|<placer order number>|<filler order number>|<cr>.

If details are not needed for the order, the order detail segment may be omitted. For example, to place an order on hold, one would transmit an ORC with the following fields completed: ORC-1-order control with a value of HD, ORC-2-placer order number, and ORC-3-filler order number.

There is some overlap between fields of the ORC and those in the order detail segments. These are described in the succeeding sections.

HL7 Attribute Table _ ORC _ Common Order

ORC use notes

1. placer order groups

The Standard supports a mechanism to collect several orders together in a group. Most often this is used to represent an "ordering session" for a single patient.

An order group is a list of orders (ORCs) associated with an ORC-4-placer group number. A group is established when the placer supplies a placer group number with the original order. The order group consists of all the ORCs and order detail segments that have the same placer group number. Orders can be removed from the group using cancel, or added using the replacement or parent-child mechanisms. New orders cannot otherwise be added to the group.

1. duplicate fields

The ORC is intended to uniformly define the fields that are common to all orders (i.e., requested services). Some ORC fields are duplicated in some order detail segments (e.g., OBR, RXO). For example, ORC-2-placer order number has the same meaning and purpose as OBR-2-placer order number field. This promotes upward compatibility with past versions and ASTM.

The rule for using these fields is that the value must appear in the order detail segment if it does not appear in the ORC. However, it is recommended to transmit the field value in both places to avoid confusion.

1. parent/child - cancel, hold, discontinue

During transmission of a request to cancel, hold, or discontinue a parent order, the request is intended to apply recursively to the parent order and all associated child orders.

For example:

1. An EKG application receives an order for three EKGs on successive mornings.

2. The EKG application creates three child orders, one for each requested EKG.

3. The first daily EKG has already been performed when a request is received to cancel the original parent order. (The parent is beyond the point of cancellation.)

4. The remaining, unperformed, children are canceled as a result of the request.

4.5.1.0 ORC field definitions

4.5.1.1 ORC-1 Order Control (ID) 00215

Definition: Determines the function of the order segment. Refer to HL7 Table 0119 - Order Control Codes And Their Meaning for valid entries. Depending on the message, the action of the control code may refer to an order or an individual service. For example, the code CA in an OMP message cancels the order. The same code in an RDS message, cancels the dispense. Very detailed explanatory notes are given at the end of this section.

This field may be considered the "trigger event" identifier for orders. The codes fall roughly into the following three categories:

1. event request

Codes like "NW" (new order) and "CA" (cancel order request) are used to initiate an event.

1. event acknowledgment

Codes like "OK" (order accepted) and "CR" (canceled as requested) are used to reply to the event request.

1. event notification

Codes like "OC" (order canceled) and "OD" (order discontinued) are used to notify other applications that an event has occurred. No application reply is necessary.

Event request codes are intended to initiate an event. Event acknowledgment codes are intended to reply to an application that requested an event. Event notification codes are intended to notify another application that, e.g., the filler has performed some action on an order that the other application, e.g., the placer, needs to know.

Fillers, placers, and other applications can use event requests, event acknowledgments, and event - notification-type trigger events interchangeably. However, certain order control codes can originate only from the filler (e.g., CR) and others can only originate from the placer (e.g., CA).

Refer to section 4.19.1 for the contents of HL7 Table 0119 _ Order Control Codes.

4.5.1.1.1 Table notes for order control codes of ORC

1. CA

A cancellation is a request not to do a previously ordered service. Confirmation of the cancellation request is provided by the filler, e.g., a message with an ORC-1-order control value of CR.

1. UC

An unable-to-cancel code is used when the ordered service is at a point that it cannot be canceled by the filler or when local rules prevent cancellation by the filler. The use of this code is dependent on the value of ORC-6-response flag.

1. DC

A discontinue request code is used to stop an ongoing ordered service. It is not the same as a cancellation request, which is used in an attempt to prevent an order from happening.

1. RP, RQ, RU, RO

A replacement is the substitution of one or more orders for one or more previously ordered services.

The replaced orders are treated as though they were canceled. If and when an ordered service can be replaced are local site-specific determinations.

Use the parent/child order control codes if the site specifies that the original order must remain intact. Do not use the replacement codes under this circumstance.

For each order to be replaced, use an ORC-1-order control value of RP (request for a replacement going to a filler) or RU (an unsolicited replacement created by the filler) used by the filler to notify the placer and/or other systems). By local agreement, the ORC segment (with RP or RU) may be followed by its original order detail segment. The ORC segments (with RP or RU) must be followed by an ORC segment with an ORC-1-order control value of RO (indicating the replacement order). By local agreement, the ORC with the RO value may be followed by an order detail segment.

For example, suppose that an ancillary application were replacing two OBR orders with three different orders. The sequence of segments would be as follows:

Figure 4-2. RU and RO usage (example)

Whether the OBR segments must be present is determined by the value of ORC-6-response flag.

The described replacement method will handle all possible cases of replacement: one-into-one, many-into-one, one-into-many, and many-into-many. If the placer sent this request to the filler with two RPs, and this was a response back from the filler to the placer, the two RUs (replaced unsolicited) would be two RQs (replaced as requested).

Figure 4-3. RQ and RO usage (example)

1. RP, RQ

The order replace request code permits the order filler to replace one or more new orders with one or more new orders, at the request of the placer application.

1. RU

The unsolicited replacement code permits the filler application to notify another application without being requested from the placer application.

1. RO, RQ

The replacement order code is sent by the filler application to another application indicating the exact replacement ordered service. It is used with the RP and RU order control codes as described above.

1. RP, RQ, RU, RO

The rules for the order numbers in ORC segments with an order control value of RO are determined by the replacement type (RP or RU).

In the case of the RU type (i.e., unsolicited replacement by the filler), the filler order number is generated as usual by the filler application. The placer order number is identical to the placer order number of the first transmitted ORC with an order control value of RU.

In the case of the RP type (i.e., a replacement request from another application to the filler), the placer order number is generated by the placer application using the procedure for new orders. The filler order number is generated by the filler application using the procedure identical for new orders.

If a replacement sequence is used in an ORU message (i.e., during results reporting), the following are the recommended segments to be used for the replacement orders:

1. ORC with an order control value of RO

2. Any OBR segments (can be replaced by any order detail segments)

3. Optionally followed by observation result segments (OBX)

4. NTE segments can appear after the OBR (or any order detail segment) or after an OBX segment as in a regular ORU message

1. PA, CH

The parent (PA) and child (CH) order control codes allow the spawning of "child" orders from a "parent" order without changing the parent (original order). One or more ORC segments with an ORC-1-order control value of PA are followed by one or more ORC segments with an ORC-1-order control value of CH. Whether OBR segments must be present is determined by the value of ORC-6-response flag.

For example, suppose that a microbiology culture produced two organisms and corresponding susceptibility reports. Then the sequence of segments would be as follows:

Figure 4-4. Example of two child orders

The assignment of placer order numbers in the parent-child paradigm depends on whether the placer or filler creates the child order and in the latter case, on whether the placer supports the SN/NA transaction. If the placer creates the child orders it will assign their placer order numbers according to its usual procedures. If the filler creates the child orders there are two possibilities: each child will inherit the placer order number of its parent, or the filler will use the SN/NA transaction to request that the placer assign a placer order number. In either case, the filler application creates the filler order numbers of the children according to its usual procedures.

Whenever a child order is transmitted in a message the ORC segment's ORC-8-parent is valued with the parent's filler order number (if originating from the filler) and with the parent's placer order number (if originating from the filler or if originating from the placer).

The parent-child mechanism can be used to "expand" a parent order (e.g., an order for three EKGs on successive mornings).

1. RE

The observations-to-follow code is used to transmit patient-specific information with an order. An order detail segment (e.g., OBR) can be followed by one or more observation segments (OBX). Any observation that can be transmitted in an ORU message can be transmitted with this mechanism. When results are transmitted with an order, the results should immediately follow the order or orders that they support.

The following example shows the sequence of segments for three Pharmacy orders. It illustrates the use of the RE code:

Figure 4-5. RE usage (example)

In this version of HL7, results can be transmitted with an order as one or more OBX segments without the necessity of including the ORC and OBR segments.

Observations can be transmitted in an ORU message without using an ORC. There are times when it is necessary to transmit information not included in the OBR segments of the ORU message. In this case, it is recommended that the ORC be included in the ORU message.

The order control value of RE is required only in ORM messages to indicate that an order is followed by observation results (OBX). The RE code is not necessary in the ORU message because it is expected that the OBR segments can be followed by observation results (OBX).

1. RR

Left in for backward compatibility. In the current version it is equivalent to an accept acknowledgment. The request-received code indicates that an order message has been received and will be processed later. The order has not yet undergone the processing that would permit a more exact response.

1. SN, NA, NW

There are three circumstances that involve requesting an order number (ORC-2-placer order number or ORC-3-filler order number):

1. When the filler application needs to request an ORC-3-filler order number from a centralized application (e.g., HIS)

2. When the filler application needs to request an ORC-2-placer order number from some other application (e.g., Order Entry)

3. When an application (not the filler application) wants to assign an ORC-3-filler order number for a new order

1) The filler application needs a centralized filler order number

SN - The send order number code provides a mechanism for the filler to request an ORC-3-filler order number from some centralized application (called "other" in the table below), such as a central HIS, by sending an ORM message containing an ORC-1-order control value of SN. This ORC has a null ORC-3-filler order number and an ORC-2-placer order number created by the filler application when the filler originates the order.

The ORM (SN type) message can be acknowledged by two methods:

By an ORR message containing an ORC-1-order control value of OK. An unsolicited ORM message can be sent at a future time, containing an ORC with ORC-1-order control value of NA.

By an ORR message containing an ORC-1-order control value of NA as described below.

NA - The number assigned code allows the "other" application to notify the filler application of the newly-assigned filler order number. ORC-1-order control contains value of NA, ORC-2-placer order number (from the ORC with the SN value), and the newly-assigned filler order number.

Note: Both the placer order number and the filler order number have the filler's application ID.

2) The filler application needs a placer order number

SN - The send order number code provides a mechanism for the filler application to request an ORC-2-placer order number from another application (called "other" in the table below) by sending an ORM message containing an ORC-1-order control value of SN. This ORC has a null ORC-2-placer order number and an ORC-3-filler order number created by the filler application when the filler originates the order.

The ORM (SN type) message can be acknowledged by two methods:

By an ORR message containing an ORC-1-order control value of OK. An unsolicited ORM message can be sent at a future time, containing an ORC-1-order control value of NA.

By an ORR message containing an ORC-1-order control value of NA as described below.

NA - The number assigned code allows the "other" application to notify the filler application of the newly-assigned ORC-2-placer order number. The ORC contains an ORC-1-order control value of NA, the newly-assigned ORC-2-placer order number, and the ORC-3-filler order number (from the ORC with the SN value).

Note: The new ORC-2-placer order number has the placer's application ID.

3) An application wants to assign a filler order number

NW - When the application creating an order (not the filler application) wants to assign a filler order number for a new order

or

RO - (RO following an RP). In this case, the "other" application completes ORC-3-filler order number, using the filler application ID as the second component of the filler order number.

1. CN

The combined result code provides a mechanism to transmit results that are associated with two or more orders. This situation occurs commonly in radiology reports when the radiologist dictates a single report for two or more exams represented as two or more orders. For example, knee and hand films for a rheumatoid arthritis patient might generate a single dictation on the part of the radiologist.

When such results are reported the CN code replaces the RE code in all but the last ORC, and the results follow the last ORC and its OBR. An example follows of a single report following three ORCs:

MSH|...<cr>

PID|...<cr>

ORC|CN|...<cr>

OBR|1|A4461XA^HIS|81641^RAD|73666^Bilateral Feet|...<cr>

ORC|CN|...<cr>

OBR|2|A4461XB^HIS|81642^RAD|73642^Bilateral Hand PA|...<cr>

ORC|RE|...<cr>

OBR|3|A4461XC^HIS|81643^RAD|73916^Bilateral Knees|...<cr>

OBX|1|CE|73916&IMP|1|Radiologist's Impression|...<cr>

OBX|2|CE|73642&IMP|1|Radiologist's Impression|...<cr>

OBX|3|FT|73642&GDT|1|Description|...<cr>

1. UA

An unable-to-accept code is used when a new order cannot be accepted by the filler. Possible reasons include requesting a prescription for a drug which the patient is allergic to or for an order which requires certain equipment resources which are not available such that the order cannot be filled. Note that this is different from the communication level acceptance as defined within the MSA segment.

1. RF

RF accommodates requests by both the filler or the placer. The filler may be requesting refill authorization from the placer. A placer system may be requesting a refill to be done by the filler system.

1. AF

AF is a response back from the placer authorizing a refill or quantity of refills.

1. DF

DF indicates that the placer will not authorize refills for the order. The order control code reason may be used to indicate the reason for the request denial. Some suggested values include:

Note that these values originate from the NCPDP SCRIPT Response Segment Code List Qualifiers.

1. FU

FU notifies the placer that the filler issued a refill for the order at the patient's request.

1. OF

OF directly responds to the placer system's request for a refill

1. UF

UF indicates an application level denial by the filler system to an authorized refill request.

1. LI, UN

Use only with Patient Care problems or goals, Chapter 12.

1. PR

PR indicates that this ORC is part of an ORU structure containing previous observation, which is embedded in the order.

At least two main use cases require that the complete results of the previous observations be transmitted with the order.

• Diagnostic laboratories referring tests to another lab for either confirmation of results (HIV, etc.) or due to not being equipped to do the tests (genetic testing, etc.).

• Diagnostic laboratories sending test results to Knowledge Bases for the automated generation of diagnostic comments for inclusion into the lab report.

1. OP, PY

These order control codes are used to communicate an order between systems where the order is intended for informational purposes. For example, an order that will be performed by a vendor outside the enterprise of communicating systems. The communicating systems may need to maintain information relative to the order for clinical continuity, but no actions to perform the ordered service are intended.

OP represents an informational version of NW, PY represents the informational-only version of RO. NW and RO table notes also apply to OP and PY, respectively.

4.5.1.2 ORC-2 Placer Order Number (EI) 00216

Definition: This field is the placer application's order number.

This field is a case of the Entity Identifier data type (See Section 2.A.28, "EI - Entity Identifier"). The first component is a string that identifies an individual order (e.g., OBR). A limit of fifteen (15) characters is suggested but not required. An implementation is HL7 compliant when the number of characters for this field is increased to accommodate applications that require a greater number of characters for the Placer order number. It is assigned by the placer (ordering application). It identifies an order uniquely among all orders from a particular ordering application. The second through fourth components contain the application ID of the placing application in the same form as the HD data type (Section 2.A.36, "HD - Hierarchic designator"). The second component, namespace ID, is a user-defined coded value that will be uniquely associated with an application. A limit of six (6) characters is suggested but not required. A given institution or group of intercommunicating institutions should establish a unique list of applications that may be potential placers and fillers and assign unique application IDs. The components are separated by component delimiters.

There are three situations in which the true placer is somewhat arbitrary (and thus not unique):

1. in ORC-1-order control value of RO, following an RU replacement;

2. in ORC-1-order control value of CH (child orders); and

3. in ORC-1-order control value of SN (send number).

See the Table Notes under ORC-1-order control for the details of how the ORC-2-placer order number is assigned in these cases.

The application ID list becomes one of the institution's master dictionary lists that is documented in Chapter 8. Since third-party applications (those other than the placer and filler of an order) can send and receive ORM and ORR messages, the placer application ID in this field may not be the same as any sending and receiving application on the network (as identified in the MSH segment).

ORC-2-placer order number is the same as OBR-2-placer order number. If the placer order number is not present in the ORC, it must be present in the associated OBR and vice versa. If both fields, ORC-2-placer order number and OBR-2-placer order number are valued, they must contain the same value. When results are transmitted in an ORU message, an ORC is not required, and the identifying placer order number must be present in the OBR segments.

These rules apply to the few other fields that are present in both ORC and OBR for upward compatibility (e.g., quantity/timing, parent numbers, ordering provider, and ordering call back numbers).

4.5.1.3 ORC-3 Filler Order Number (EI) 00217

Definition: This field is the order number associated with the filling application. It is a case of the Entity Identifier data type (Section 2.A.28). Its first component is a string that identifies an order detail segment (e.g., OBR). A limit of fifteen (15) characters is suggested but not required. An implementation is HL7 compliant when the number of characters for this field is increased to accommodate applications that require a greater number of characters for the Filler order number. It is assigned by the order filler (receiving) application. This string must uniquely identify the order (as specified in the order detail segment) from other orders in a particular filling application (e.g., clinical laboratory). This uniqueness must persist over time.

The second through fourth components contain the filler application ID, in the form of the HD data type (see Section 2.A.36, "HD - hierarchic designator"). The second component is a user-defined coded value that uniquely defines the application from other applications on the network. A limit of six (6) characters is suggested but not required. The second component of the filler order number always identifies the actual filler of an order.

A given institution or group of intercommunicating institutions should establish a list of applications that may be potential placers and fillers of orders and assign each a unique application ID. The application ID list becomes one of the institution's master dictionary lists that is documented in Chapter 8. Since third- party applications (those other than the placer and filler of an order) can send and receive ORM and ORR messages, the filler application ID in this field may not be the same as any sending and receiving application on the network (as identified in the MSH segment).

ORC-3-filler order number is the same as OBR-3-filler order number. If the filler order number is not present in the ORC, it must be present in the associated OBR. (This rule is the same for other identical fields in the ORC and OBR and promotes upward and ASTM compatibility.) This is particularly important when results are transmitted in an ORU message. In this case, the ORC is not required and the identifying filler order number must be present in the OBR segments.

The filler order number (OBR-3 or ORC-3) also uniquely identifies an order and its associated observations. For example, suppose that an institution collects observations from several ancillary applications into a common database and this common database is queried by yet another application for observations. In this case, the filler order number and placer order number transmitted by the common database application would be that of the original filler and placer, respectively, rather than a new one assigned by the common database application.

Similarly, if a third-party application, not the filler or placer, of an order were authorized to modify the status of an order (say, cancel it), the third-party application would send the filler an ORM message containing an ORC segment with ORC-1-order control equal to "CA" and containing the original placer order number and filler order number, rather than assign either itself.

4.5.1.4 ORC-4 Placer Group Number (EI) 00218

Definition: This field allows an order placing application to group sets of orders together and subsequently identify them. It is a case of an Entity Identifier data type (2.A.28).

The first component is a string that uniquely identifies all order groups from the given placer application. A limit of fifteen (15) characters is suggested but not required. It is assigned by the placer application and may come from the same series as the placer order number of the ORC, but this is not required.

The second through fourth components constitute a placer application ID identical to the analogous components of ORC-2-placer order number. Order groups and how to use them are described in detail in Section 4.5.1, "ORC - Common Order Segment."

4.5.1.5 ORC-5 Order Status (ID) 00219

Definition: This field specifies the status of an order. Refer to HL7 Table 0038 - Order status for valid entries. The purpose of this field is to report the status of an order either upon request (solicited), or when the status changes (unsolicited). It does not initiate action. It is assumed that the order status always reflects the status as it is known to the sending application at the time that the message is sent. Only the filler can originate the value of this field.

Although HL7 Table 0038 - Order status contains many of the same values contained in HL7 Table 0119 - Order control codes and their meaning, the purpose is different. Order status may typically be used in a message with an ORC-1-order control value of SR or SC to report the status of the order on request or to any interested party at any time.

HL7 Table 0038 - Order status

Definition: This field allows the placer (sending) application to determine the amount of information to be returned from the filler. Sometimes the requested level of response may not be possible immediately, but when it is possible, the filler (receiving) application must send the information. When the field is null, D is the default value of the field. Refer to HL7 Table 0121 - Response flag for valid entries.

HL7 Table 0121 - Response flag

Definition: This field is retained for backward compatibility only. The reader is referred to the TQ1 and TQ2 segments described in sections 4.5.4 and 4.5.5 respectively.

This field determines the priority, quantity, frequency, and timing of an atomic service. Order segments should be thought of as describing an atomic service. It is a composite field that is defined in detail in Section 4.3, "Quantity/Timing (TQ) Data Type Definition."

For example, if an OBR segment describes a unit of blood, this field might request that three (3) such units be given on successive mornings. In this case ORC-7-quantity/timing would be "1^QAM^X3". ORC-7-quantity/timing is the same as OBR-27-quantity/timing.

To send information about "collection time", use the 'text' component of the TQ data type in either the ORC-7 or OBR-27.

ORC-7-quantity/timing is the same as OBR-27-quantity/timing. If the ORC-7 and OBR-27 are both valued, then both should be valued exactly the same. If the quantity/timing is not present in the ORC, it must be present in the associated OBR. (This rule is the same for other identical fields in the ORC and OBR and promotes upward and ASTM compatibility.) This is particularly important when results are transmitted in an ORU message. In this case, the ORC is not required and the identifying filler order number must be present in the OBR segments.

4.5.1.8 ORC-8 Parent (EIP) 00222

Definition: This field relates a child to its parent when a parent-child relationship exists. The parent-child mechanism is described under ORC-1-order control notes.

The first component has the same format as ORC-2-placer order number (Section 4.5.1.2, "Placer Order Number (EI) 00216)." The second component has the same format as ORC-3-filler order number (Section 4.5.1.3, "Filler Order Number (EI) 00217)_. The components of the placer order number and the filler order number are transmitted in sub-components of the two components of this field.

ORC-8-parent is the same as OBR-29-parent. If the parent is not present in the ORC, it must be present in the associated OBR. (This rule is the same for other identical fields in the ORC and OBR and promotes upward and ASTM compatibility.) This is particularly important when results are transmitted in an ORU message. In this case, the ORC is not required and the identifying filler order number must be present in the OBR segments.

4.5.1.9 ORC-9 Date/Time of Transaction (TS) 00223

Definition: This field contains the date and time of the event that initiated the current transaction as reflected in ORC-1 Order Control Code. This field is not equivalent to MSH-7 Date and Time of Message which reflects the date/time of the physical message.

4.5.1.10 ORC-10 Entered By (XCN) 00224

Definition: This field contains the identity of the person who actually keyed the request into the application. Note that this refers to the current transaction as reflected in ORC-1 Order Control Code. It provides an audit trail in case the request is entered incorrectly and the ancillary department needs to clarify the request. By local agreement, either the ID number or name component may be omitted.

4.5.1.11 ORC-11 Verified By (XCN) 00225

Definition: This field contains the identity of the person who verified the accuracy of the entered request. Note that this refers to the current transaction as reflected in ORC-1 Order Control Code. It is used in cases where the request is entered by a technician and needs to be verified by a higher authority (e.g., a nurse). By local agreement, either the ID number or name component may be omitted.

4.5.1.12 ORC-12 Ordering Provider (XCN) 00226

Definition: This field contains the identity of the person who is responsible for creating the request (i.e., ordering physician).

ORC-12-ordering provider is the same as OBR-16-ordering provider. If the ordering provider is not present in the ORC, it must be present in the associated OBR. (This rule is the same for other identical fields in the ORC and OBR and promotes upward and ASTM compatibility.) This is particularly important when results are transmitted in an ORU message. In this case, the ORC is not required and the identifying filler order number must be present in the OBR segments.

4.5.1.13 ORC-13 Enterer's Location (PL) 00227

Definition: This field specifies the location (e.g., nurse station, ancillary service location, clinic, floor) where the person who entered the request was physically located when the order was entered. Note that this refers to the current transaction as reflected in ORC-1 Order Control Code. Only those subcomponents relevant to enterer's location should be valued (commonly nursing unit; facility; building; floor). The person who entered the request is defined in ORC-10-entered by.

4.5.1.14 ORC-14 Call Back Phone Number (XTN) 00228

Definition: This field contains the telephone number to call for clarification of a request or other information regarding the order. ORC-14-call back phone number is the same as OBR-17-order callback phone number.

4.5.1.15 ORC-15 Order Effective Date/Time (TS) 00229

Definition: This field contains the date/time that the changes to the request took effect or are supposed to take effect.

If ORC-9-date/time of transaction is after or equal to ORC-15-order effective date/time, the data values in the ORC and its subordinate segments took effect on the order effective date/time.

If ORC-9-date/time of transaction is before the time specified in ORC-15-order effective date/time, the data values in ORC and its subordinate segments are planned to take effect on the order effective date/time.

If ORC-15-order effective date/time is left blank, its value is assumed to be equal to that specified in ORC-9-date/time of transaction or MSH-7-date/time of message if the transaction date/time is blank.

In the case where the time specified in ORC-15-order effective date/time (for the order control code event in the same ORC segment) is different from the corresponding date/time in ORC-7-quantity/timing, the time specified in ORC-15-order effective date/time takes precedence. Thus if the ORC event is a discontinue request to the filler for a continuing order, and the order-effective date/time is prior to the end date/time of ORC-7-quantity/timing, the order effective date/time should take precedence. If the order identified in the ORC has children, the children which have not started should be canceled; if there is a child in process, it should be discontinued; if a child has progressed beyond the point where it can be discontinued, its status is unaffected.

4.5.1.16 ORC-16 Order Control Code Reason (CE) 00230

Definition: This field contains the explanation (either in coded or text form) of the reason for the order event described by the order control code (HL7 Table 0119). Whereas an NTE after the order-specific segment (e.g., RXO, ORO, OBR) would provide a comment for that specific segment, the purpose of the order control code reason is only to expand on the reason for the order event.

ORC-16-order control code reason is typically not valued when ORC-1-order control is NW, although it could be. In the case of a canceled order, for example, this field is commonly used to explain the cancellation. A Pharmacy system that canceled a drug order from a physician because of a well documented allergy would likely report the fact of the allergy in this field.

If it canceled the order because of a drug interaction this field might contain at least the names (and codes, if needed) of the interacting substances, the text describing the interaction, and the level of severity of the interaction.

4.5.1.17 ORC-17 Entering Organization (CE) 00231

Definition: This field identifies the organization that the enterer belonged to at the time he/she enters/maintains the order, such as medical group or department. The person who entered the request is defined in ORC-10 -entered by.

4.5.1.18 ORC-18 Entering Device (CE) 00232

Definition: This field identifies the physical device (terminal, PC) used to enter the order.

4.5.1.19 ORC-19 Action By (XCN) 00233

Definition: This field contains the identity of the person who initiated the event represented by the corresponding order control code. For example, if the order control code is CA (cancel order request), this field represents the person who requested the order cancellation. This person is typically a care provider but may not always be the same as ORC-12 ordering provider.

4.5.1.20 ORC-20 Advanced Beneficiary Notice Code (CE) 01310

Definition: This field indicates the status of the patient's or the patient's representative's consent for responsibility to pay for potentially uninsured services. This element is introduced to satisfy CMS Medical Necessity requirements for outpatient services. This element indicates (a) whether the associated diagnosis codes for the service are subject to medical necessity procedures, (b) whether, for this type of service, the patient has been informed that they may be responsible for payment for the service, and (c) whether the patient agrees to be billed for this service. The values for this field are drawn from User-Defined Table 0339 _ Advanced Beneficiary Notice Code.

User-defined Table 0339 _ Advanced Beneficiary Notice Code

Definition: This field contains the name of the facility placing the order.

4.5.1.22 ORC-22 Ordering Facility Address (XAD) 01312

Definition: This field contains the address of the facility placing the order.

4.5.1.23 ORC-23 Ordering Facility Phone Number (XTN) 01313

Definition: This field contains the telephone number of the facility placing the order.

4.5.1.24 ORC-24 Ordering Provider Address (XAD) 01314

Definition: This field contains the address of the care provider requesting the order.

4.5.1.25 ORC-25 Order Status Modifier (CWE) 01473

Definition: This field is a modifier or refiner of the ORC-5-Order status field. This field may be used to provide additional levels of specificity or additional information for the defined order status codes. Unlike the Order Status field, which is controlled by an HL7 defined table, this field is a CE data type allowing applications to support an unlimited library of Order Status Modifier codes.

Usage Rule: This field may only be populated if the ORC-5-Order Status field is valued.

Examples: An LIS is processing an order with an order status of IP may send an update using the order status modifier to indicate the progress of the order through the laboratory or to indicate that the order has been sent to an external laboratory. Another example using the non-medical orders would be where a phone has been ordered delivered to a patient's room, but has been disconnected temporarily. The ORC-5-Order status indicates IP and the ORC-25-Order status modifier would indicate a disconnected status. A third example involves pharmacy dispenses. It is sometimes not enough to know the prescription is being dispensed. The ORC-25-Order status modifier would indicate if a label had been printed, the prescription filled, or the prescription sold.

4.5.1.26 ORC-26 Advanced Beneficiary Notice Override Reason (CWE) 01641

Definition: This field contains the reason why the patient did not sign an Advanced Beneficiary Notice. The reason may be coded or it may be a free text entry. Refer to HL7 Table 0552 _ Advanced beneficiary notice override reason.

Condition: This field is required if the value of ORC-20 Advanced Beneficiary Notice Code indicates that the notice was not signed. For example, additional qualifying or explanatory information would be justified if ORC-20 was populated with the values "3" or "4" in User-defined Table 0339 _ Advanced Beneficiary Notice Code, or similar values in related external code tables.

HL7 Table 0552 - Advanced beneficiary notice override reason

Definition: This field specifies the date/time the filler expects the services to be available. For example when a prescription is ready for pickup or when a supply will be sent or picked up, or for when a laboratory result is expected to be available.

4.5.1.28 ORC _28 Confidentiality Code (CWE) 00615

Definition: This field contains information about the level of security and/or sensitivity surrounding the order (e.g., highly sensitive, not sensitive, sensitive, etc.). Refer to HL7 Table 0177 _ Confidentiality Code for allowed values. The specific treatment of data with a particular confidentiality level is subject to site-specific negotiation.

4.5.1.29 ORC _ 29 Order Type (CWE) 01643

Definition: This field indicates whether the order is to be executed in an inpatient setting or an outpatient setting. If this field is not valued, the system default is assumed. Refer to HL7 Table 0482 _ Order Type for suggested values.

Examples: Before discharge an order is placed for follow-up physical therapy, or to pick up a prescription at a community pharmacy. The patient is an inpatient according to PV1, but the order is an outpatient order.

HL7 Table 0482 - Order Type

Definition: This field indicates the form of authorization a recorder had from the responsible practitioner to create or change an order. Refer to HL7 Table 0483 Authorization Mode for suggested values.

HL7 Table 0483 _ Authorization Mode

The BLG segment is used to provide billing information, on the ordered service, to the filling application.

HL7 Attribute Table _ BLG _ Billing