TCD - Test Code Detail Segment

The test code detail segment contains the data necessary to perform operations or calculations, or execute decisions by the laboratory automation system, and which are not supported by the original HL7 segments related to orders (ORC, OBR). For detail of use see messages of laboratory orders and observations in chapters 4 and 7.

HL7 Attribute Table - TCD - Test Code Detail Segment

Seq#	Data Element Name	DataType	Usage	Vocabulary	Cardinality	Item #	Length	C.LEN	Flags
TCD
1	Universal Service Identifier	CWE	R	0612	[1..1]	00238
2	Auto-Dilution Factor	SN	O		[0..1]	01420
3	Rerun Dilution Factor	SN	O		[0..1]	01421
4	Pre-Dilution Factor	SN	O		[0..1]	01422
5	Endogenous Content of Pre-Dilution Diluent	SN	O		[0..1]	01413
6	Automatic Repeat Allowed	ID	O	0136(R) Yes/no Indicator(Required)	[0..1]	01416	[1..1]
7	Reflex Allowed	ID	O	0136(R) Yes/no Indicator(Required)	[0..1]	01424	[1..1]
8	Analyte Repeat Status	CWE	O	0389(R) Analyte Repeat Status(Required)	[0..1]	01425
9	Specimen Consumption Quantity	CQ	O		[0..1]	03490
10	Pool Size	NM	O		[0..1]	03493
11	Auto-Dilution Type	CWE	O	0945 Auto-Dilution Type	[0..1]	03494

TCD-1: Universal Service Identifier (CWE) 00238

Definition: This field identifies the test code that information is being transmitted about. Refer to Table 0789 - Universal Service Identifier in Chapter 2C for valid values.

TCD-2: Auto-Dilution Factor (SN) 01420

Definition: This field is the value that is to be used as the factor for automatically diluting a particular specimen by an instrument for this particular test code. (See examples in definition of 13.4.3.29, "SAC-29 Dilution Factor (SN) 01356," in the "Specimen Container Detail Segment.")

TCD-3: Rerun Dilution Factor (SN) 01421

Definition: This field is the value that is to be used as the factor for automatically diluting a particular specimen in case of rerun for this particular test code.

TCD-4: Pre-Dilution Factor (SN) 01422

Definition: This field is the value that is to be used as the factor for a particular specimen that is delivered to the automated system as pre-diluted for this particular test code.

TCD-5: Endogenous Content of Pre-Dilution Diluent (SN) 01413

Definition: This field represents the rest concentration of the measured test in the diluent. It is the value that is to be used for calculation of the concentration of pre-diluted specimens for this particular test code.

TCD-6: Automatic Repeat Allowed (ID) 01416

Definition: This field identifies whether or not automatic repeats are to be initiated for this particular specimen for this particular test code. Refer to HL7 Table 0136 -Yes/no Indicator for valid values.

TCD-7: Reflex Allowed (ID) 01424

Definition: This field identifies whether or not automatic or manual reflex testing is to be initiated for this particular specimen. Refer to HL7 Table 0136 -Yes/no Indicator for valid values.

TCD-8: Analyte Repeat Status (CWE) 01425

Definition: This field identifies the repeat status for the analyte/result (e.g., original, rerun, repeat, reflex). Refer to HL7 Table 0389 – Analyte Repeat Status in Chapter 2C, Code Tables, for valid values.

For purpose of this chapter we assume the following:

• Repeated test without dilution — performed usually to confirm correctness of results (e.g., in case of results flagged as "Panic" or mechanical failures).

• Repeated test with dilution — performed usually in the case the original result exceeded the measurement range (technical limits).

• Reflex test — this test is performed as the consequence of rules triggered based on other test result(s).

TCD-9: Specimen Consumption Quantity (CQ) 03490

Definition: The specimen consumption quantity determines how much of the specimen shall be consumed in each run of the test. For some types of equipment, observation accuracy depends on this parameter.

TCD-10: Pool Size (NM) 03493

Definition: In order submission messages, this field defines the maximal size of the pool where the given specimen may be combined into. In result submission messages, this field defines the actual size of such pool.

TCD-11: Auto-Dilution Type (CWE) 03494

Definition: This field contains a vendor-defined code of the auto-dilution factor pre-configured on the instrument, which can be used instead of TCD-2 “Auto-Dilution Factor”. Refer to User-defined Table 0945– Auto Dilution Type in Chapter 2C, Code Tables, for suggested values.

If both TCD-2 “Auto-Dilution Factor” and TCD-11 “Auto-Dilution Type” are populated, they shall not contradict each other.