5 Observation Ordering

5.1 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.  This document focuses on tests in the laboratory.

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. 

In HL7 V 2.4 new message types were introduced to accommodate automated laboratory equipment.  These new message types are:

• OMG^O19—General clinical order message.
  
• ORG^O20—General clinical order acknowledgement message.
• OML^O21—Pathology order.
• ORL^O22—Pathology order response.
• OUL^R21—Unsolicited pathology observation.
  

These new message types contain the following new segments:

• SAC—Specimen and container details.
  
• TCD—Test code details.
• SID—Substance identifier.

For further detail on these segments refer to HL7 V2.4 chapter 13 - Laboratory Automation. These new segments, message types and trigger event codes should not be used in the Australian context unless there is mutual agreement. 

In the Australian context the following message type and trigger event codes shall be used:

• ORM^O01 - General Order Message
  
• ORU^R01 - Observation Result (Unsolicited)
• ORR^O02 - Order Receipt
• ACK^R01 - Acknowledgment Result (HL7 V2.4, section 7.3.1)
• ACK^O01 - General Acknowledgement or order

5.1.1 Preface (organization of this chapter)

This chapter has a General section that describes the trigger events, message definitions, segments and examples for the specific type of order messages. The 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.

5.1.2 Glossary

5.1.2.1 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

5.1.2.2 Observation segment:

An OBX segment defined in Section 4: Observation Reporting

5.1.2.3 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.

5.1.2.4 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.

5.1.2.5 Placer:

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

5.1.2.6 Placer order group:

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

5.2 ORM - general order message (event O01)   

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. 

Note: the ORM message contains the the tests ordered by the placer in the OBR segment, but it has no influence on the format or presentation of the report.

ORM^O01^ORM_O01          General Order Message 
MSH
[
    PID                  Message Header
    [PD1]                Additional Demographics
    [
     PV1                 Patient Visit
     [PV2]               Patient Visit- Additional Info
	]
    [{
	  IN1                Insurance
      [IN2]              Insurance Additional Info
      [IN3               Insurance Add'l Info - Cert. 
     }
	]
    [GT1]                Guarantor
    [{AL1}]              Allergy Information
]
{
    ORC                  Common Order
    OBR                  Order Detail Segment
    [CTD]                Contact Data
    [{DG1}]              Diagnosis
    [{OBX}]              Observation/Result
    [{FT1}]              Financial Transaction
    [{CTI}]              Clinical Trial Identification
    [BLG]                Billing Segment 
}

This message struct differs from the international definition in that NTE segments have been removed and for use in pathology ordering OBR has become the default order detail segment. The same message can be used for medication and diet orders where the OBR is replaced with other order detail segments.

The initial response to an order is usually a generic ACK^O01 indicating Acceptance of the message, but can be an application level ORR^O01 message

ACK^O01^ACK         General Acknowledgment
MSH                 Message Header
MSA                 Message Acknowledgment
[ ERR ]             Error

The Filler application responds to the Order and can potentially return further details, such as the Filler Order Number. The ORC/OBR segments are optional however. This message is usually delayed until the specimen has been collected/received and a laboratory number has been allocated. The Filler Order number is not the same as the Laboratory Number but often includes the Lab No as part of the identifier.

ORR^O02^ORR_O02      General Order Acknowledgment
MSH                  Message Header 
MSA                  Message Acknowledgment
[ERR]                Error
[
[PID                 Patient Identification
  {
  ORC                Common Order
  OBR                Order Detail Segment
  }
]

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

OSQ^Q06^OSQ_Q06       Order Status Query
MSH                   Message Header
QRD                   Query Definition 
[ QRF ]               Query Filter
[ DSC ]               Continuation Pointer 

OSQ^Q06^OSQ_Q06            Order Status Response 
MSH                        Message Header
MSA                        Message Acknowledgment
[ERR]                      Error
QRD                        Query Definition
[QRF]                      Query Filter
[
    [PID]                  Patient Identification 	
    {  	
      ORC                  Common Order 
      OBR                  Order Detail 
	  [{OBX}]              Observation result/detail 
      [{CTI}]              Clinical Trial Identification	
    } 	
]	
[DSC]                      Continuation Pointer

The QRD and QRF segments are defined in 2.1 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. 4.4.3.1 Query usage notes

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.” in the HL7 International V2.4 Standard.

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.

5.4 ORC SEGMENT

The ORC segment is common to many order messages.   

5.4.1 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.

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.

In the outpatient Medicare payment setting, a HL7 pathology order relates to a single episode - instance or occurrence.  As compared to the hospital inpatient setting the request may be part of a larger episode of care and hence only the placer order number is used and not a placer group number. Generally there is more than one test per pathology request form, e.g. FBC, UE and LFT, where each test must be ordered using an ORC/OBR segment pair.  In the FBC, UE and LFT example the order would be contained in one MSH segment with 3 separate ORC/OBR pairs for each orderable request. The ORC segment contains the order identification information where the Placer Order Number identifies each order in both the ORC and OBR segments. The episode is identified by a Placer Group Number contained in the ORC segment only. For each requested test the same Placer Order Number can be used or different numbers can be allocated to each requested test. The recommended approach is that different Placer Order Numbers are used for each test ordered. The Placer Group Number links all orders for the patient episode into a single request.

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

5.4.1.0 ORC field definitions

HL7 Attribute Table – ORC – Common Order

ORC use notes:

* ALERT: Variance with HL7 2.4 International. 

** ALERT: The field length of ORC-2, ORC-3 and ORC-4 of 250 characters for Australian usage is a variance to the HL7 V 2.4 field length of 22 characters.

a) 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.

b) 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.

c) 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 ECG application receives an order for three ECGs on successive mornings.

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

3) The first daily ECG 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 cancelled as a result of the request.

5.4.1.1 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/ORM 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:

a) event request

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

b) event acknowledgment

Codes like “OK” (order accepted) and “CR” (cancelled as requested) are used to reply to the event request.

c) event notification

Codes like “OC” (order cancelled) 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 HL7 Table 0119 - Order control codes. 

5.5.1.1.1 Table notes for order control codes of ORC

a) 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.

b) UC

An unable-to-cancel code is used when the ordered service is at a point that it cannot be cancelled 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.

c) 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.

d) 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 cancelled. 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 5-1. 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 5-2. RQ and RO usage (example)

       e) 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.

f) RU

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

g) 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.

h) 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)

i) 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 5-3. 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).

j) 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.

 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).

k) 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.

l) 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:

i) 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.

ii) 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:

i) 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.

ii) 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. 

 m) 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 resented 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>

n) 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.

o) 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.

p) AF

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

q) 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:

AA Patient unknown to the provider

AB Patient never under provider care

AC Patient no longer under provider care

AD Patient has requested refill too soon

AE Medication never prescribed for the patient

AF Patient should contact provider first

AG Refill not appropriate

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

r) FU

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

s) OF

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

t) UF

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

u) LI, UN

Use only with Patient Care problems or goals, Chapter 12 of the International Standard v2.4.

v) 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.

5.4.1.2 ORC-2 Placer order number (EI) 00216

Components: <entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID (ST)> ^ <universal ID type (ID)>

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

This field is a case of the Entity Identifier data type (See Data types, “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  ID of the placer in the same form as the HD data type (Data types, “HD - Hierarchic designator”). 

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

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

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

c) 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.

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).

To ensure uniqueness of the identifying code of the order number, a suggested method is to use the first two characters of a town prefixed to the surgery telephone number eg IP38100001.  For hospital an appropriate site code may be MH-CN for Mater Hospital Cairns and MH-WL for Mater Hospital Woolongong. 

5.4.1.3 ORC-3 Filler order number (EI) 00217

Components: <entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID (ST)> ^ <universal ID type (ID)>

Definition: This field is the order number associated with the filling application. It is a case of the EI - Entity Identifier data type . 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 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 of the Internatiional standard v2.4. 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.

To ensure uniqueness of the identifying code of the filler number, the pathology provider should use their NATA accreditation number. For example, |Good Health Pathology^123546^AUSNATA|

5.4.1.4 ORC-4 Placer group number (EI) 00218

Components: <entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID (ST)> ^ <universal ID type (ID)>

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

The first component is a string that uniquely identifies all order groups from the given placer application. 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 .

The Placer Group Number links the group of ordered tests into a single episode. It is recommended that the placer group number be the same as the placer order number minus the 'counter' component. 
For example, if ORC-2 is .... 3456-1^38100001^IP.... then ORC-4 is  .... 3456^38100001^IP....

5.4.1.5 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

5.4.1.6 ORC-6 Response flag (ID) 00220

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

5.4.1.7 ORC-7 Quantity/timing (TQ) 00221

Components: <quantity (CQ)> ^ <interval (CM)> ^ <duration (ST)> ^ <start date/time (TS)> ^ <end date/time (TS)> ^ <priority (ST)> ^ <condition (ST)> ^ <text (TX)> ^ <conjunction

(ID)> ^ <order sequencing (CM)> ^ <occurrence duration (CE)> ^ <total occurrences (NM)>

Definition: 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 Data types, “Quantity/Timing (TQ) 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.

5.4.1.8 ORC-8 Parent (CM) 00222

Components: <parent's placer order number (EI)> ^ <parent's filler order number (EI)>

Subcomponents of parent’s placer order number: <entity identifier (ST)> & <namespace ID (IS) & <universal ID (ST)> & <universal ID type (IS)>

Subcomponents of parent’s filler order number: <entity identifier (ST)> & <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (IS)>

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  The second component has the same format as ORC-3-filler order number. 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.

5.4.1.9 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.

5.4.1.10 ORC-10 Entered by (XCN) 00224

Components: In Version 2.3 and later, use instead of the CN data type. <ID number (ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III) (ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^ <source table (IS)> ^ <assigning authority (HD)> ^ <name type code (ID)>^ <identifier check digit (ST)> ^ <code identifying the check digit scheme employed (ID)> ^ <identifier type code (IS)> ^ <assigning facility (HD)> ^ <name representation code (ID)> ^ <name context (CE)> ^ <name validity range (DR)> ^ < name assembly order (ID)> Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

Subcomponents of assigning facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

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.

In the Australian context, where possible, this XCN data must be populated using the method described in A10.1.2.1 XCN Datatype.

5.4.1.11 ORC-11 Verified by (XCN) 00225

Components: In Version 2.3 and later, use instead of the CN data type. <ID number (ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or further given names or initials thereof

(ST)> ^ <suffix (e.g., JR or III) (ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g.,MD) (IS)> ^ <source table (IS)> ^ <assigning authority (HD)> ^ <name type code (ID)> ^ <identifier check digit (ST)> ^ <code identifying the check digit scheme employed(ID)> ^ <identifier type code (IS)> ^ <assigning facility (HD)> ^ <name representation code (ID)> ^ <name context (CE)> ^ <name validity range (DR)> ^ < name assembly order (ID)>

Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

Subcomponents of assigning facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

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.

In the Australian context, where possible, this XCN data must be populated using the method described in A10.1.2.1 XCN Datatype.

5.4.1.12 ORC-12 Ordering provider (XCN) 00226

Components: In Version 2.3 and later, use instead of the CN data type. <ID number (ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III) (ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^ <source table (IS)> ^ <assigning authority (HD)> ^ <name type code (ID)>^ <identifier check digit (ST)> ^ <code identifying the check digit scheme employed (ID)> ^ <identifier type code (IS)> ^ <assigning facility (HD)> ^ <name representation code (ID)> ^ <name context (CE)> ^ <name validity range (DR)> ^ < name assembly order (ID)>

Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

Subcomponents of assigning facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

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.

In the Australian context, where possible, this XCN data must be populated using the method described in A10.1.2.1 XCN Datatype.

This field should be valued if known.

5.4.1.13 ORC-13 Enterer’s location (PL) 00227

Components: <point of care (IS)> ^ <room (IS)> ^ <bed (IS)> ^ <facility (HD)> ^ <location status (IS)> ^ <person location type (IS)> ^ <building (IS)> ^ <floor (IS)> ^ <location description (ST)>

Subcomponents of facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

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 .

5.5.1.14 ORC-14 Call back phone number (XTN) 00228

Components: [N NN] [(999)]999-9999 [X99999] [B99999] [C any text] ^ <telecommunication use code (ID)> ^ <telecommunication equipment type (ID)> ^ <email address (ST)> ^ <country code (NM)> ^ <area/city code (NM)> ^ <phone number (NM)> ^ <extension (NM)> ^ <any text (ST)>

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.

5.4.1.15 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.

5.4.1.16 ORC-16 Order control code reason (CE) 00230

Components: <identifier (ST)> ^ <text (ST)> ^ <name of coding system (IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^ <name of alternate coding system (IS)>

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 - Order control codes ). 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.

5.4.1.17 ORC-17 Entering organization (CE) 00231

Components: <identifier (ST)> ^ <text (ST)> ^ <name of coding system (IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^ <name of alternate coding system (IS)>

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.

5.4.1.18 ORC-18 Entering device (CE) 00232

Components: <identifier (ST)> ^ <text (ST)> ^ <name of coding system (IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^ <name of alternate coding system (IS)>

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

5.4.1.19 ORC-19 Action by (XCN) 00233

Components: In Version 2.3 and later, use instead of the CN data type. <ID number (ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III) (ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g.,MD) (IS)> ^ <source table (IS)> ^ <assigning authority (HD)> ^ <name type code (ID)>^ <identifier check digit (ST)> ^ <code identifying the check digit scheme employed (ID)> ^ <identifier type code (IS)> ^ <assigning facility (HD)> ^ <name representation code (ID)> ^ <name context (CE)> ^ <name validity range (DR)> ^ < name assembly order (ID)>

Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

Subcomponents of assigning facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

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.

In the Australian context, where possible, this XCN data must be populated using the method described in A10.1.2.1 XCN Datatype.

5.4.1.20 ORC-20 Advanced beneficiary notice code (CE) 01310

Components: <identifier (ST)> ^ <text (ST)> ^ <name of coding system (IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^ <name of alternate coding system (IS)>

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 HCFA 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 

5.4.1.21 ORC-21 Ordering facility name (XON) 01311

Components: <organization name (ST)> ^ <organization name type code (IS)> ^ <ID Number (NM)> ^<check digit (NM)> ^ <code identifying the check digit scheme employed (ID)> ^ <assigning authority (HD)> ^ <identifier type code (IS)> ^ <assigning facility ID (HD)>^ <name representation code (ID)>

Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)>

Subcomponents of assigning facility: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)>

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

5.4.1.22 ORC-22 Ordering facility address (XAD) 01312

Components: In Version 2.3 and later, replaces the AD data type. <street address (SAD)> ^ <other designation (ST)> ^ <city (ST)> ^ <state or province (ST)> ^ <zip or postal code (ST)> ^ <country (ID)> ^ < address type (ID)> ^ <other geographic designation (ST)> ^<county/parish code (IS)> ^ <census tract (IS)> ^ <address representation code (ID)>^ <address validity range (DR)>

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

5.4.1.23 ORC-23 Ordering facility phone number (XTN) 01313

Components: [N NN] [(999)]999-9999 [X99999] [B99999] [C any text] ^ <telecommunication use code (ID)> ^ <telecommunication equipment type (ID)> ^ <email address (ST)> ^ <country code (NM)> ^ <area/city code (NM)> ^ <phone number (NM)> ^ <extension (NM)> ^ <any text (ST)>

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

5.4.1.24 ORC-24 Ordering provider address (XAD) 01314

Components: In Version 2.3 and later, replaces the AD data type. <street address (SAD)> ^ <other designation (ST)> ^ <city (ST)> ^ <state or province (ST)> ^ <zip or postal code (ST)> ^ <country (ID)> ^ < address type (ID)> ^ <other geographic designation (ST)> ^<county/parish code (IS)> ^ <census tract (IS)> ^ <address representation code (ID)> ^ <address validity range (DR)>

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

5.4.1.25 ORC-25 Order status modifier (CWE) 01473

Components: <identifier (ST)> ^ <text (ST)> ^ <name of coding system (IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^ <name of alternate coding system (IS)> ^ <coding system version ID (ST)> ^ alternate coding system version ID (ST)> ^ <original text (ST)>

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.

5.5 Australian usage notes

To implement ordering between placers and Australian Pathology providers it is suggested that the process be simplified in the following ways:

APUTS order codes should be used in the OBR-4 Universal Service Identifier of the orders unless none are found suitable for eg. new tests. The RCPA Board approved Requesting Pathology Terminology Reference Set is available on the National Clinical Terminology Service. 

State changes should be limited to NW (new) and CA (Cancel) from placer to filler. To replace a test cancel the previous order and create a new order.

It is common that the returning results (in ORU^R01 message) are not identical to what is ordered. At times the Filler will select a more appropriate test and in many case one result will satisfy multiple orders. Add on tests are also performed at times. The granularity of ordering is often controlled by Medicare regulations. Because of these factors a mechanism is required to allow placers to know their order has be dealt with, even if the tests performed by the filler do not match the ordered test exactly. (and will have a different OBR-4 Universal Service Identifier)

When tests are replaced by the Filler an OBR Segment with no associated OBX segments, (but identical OBR-4 Universal Service Identifier to the order) will be returned to mark the order as complete. The tests actually performed are transmitted as normal and may also include the placer order number but in many cases will not as one panel (eg E/LFTS) will replace orders for individual components (eg U&Es and LFTs). In the original order, each of these components will have been transmitted in a separate OBR with a unique Placer order Number. The placer Group number can be used to relate results without a matching order to the original requests. When copy doctors are used facilities may receive Placer Order Numbers and Placer Group numbers that are only relevant to the ordering provider. The value of the HD component of the EI data types will indicate the facility responsible for the order.

Orders being transmitted directly to the Filler are addressed using MSH-6 Receiving Facility.

Desired Copy Doctors for the result  should be transmitted using OBR-28 Result Copies To in the order.

Placer Order Numbers, and Placer Group numbers must be unique within the facility producing the order and must be qualified by the HD component of the EI datatype, which is the facility ID. In most cases this would be identical to the MSH Sending Facility.

Any complex clinical information required by the filler to interpret to results of the requested test can be transmitted to the filler in the OBX segments that follow the OBR segment. General text notes relating to the order can be transmitted in OBR-13 Relevant Clinical Info.

Billing Information is conveyed from the placer to the filler using the PV1 segment and this is detailed in Chapter 2 Patient Administration for Pathology.