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OM6 - Observations That Are Calculated From Other Observations Segment

The Technical Steward for the OM6 segment is Orders and Observations.

This segment contains the information about quantities that are derived from one or more other quantities or direct observations by mathematical or logical means.

HL7 Attribute Table - OM6 - Observations that are Calculated from Other Observations Segment
Seq# DataElement Description Must Implement Flags Cardinality Length C.LEN Vocabulary DataType
OM6
1 00586 Sequence Number - Test/Observation Master File = [0..1] 4 NM
2 00657 Derivation Rule [0..1] TX

OM6-1: Sequence Number - Test/Observation Master File (NM) 00586

(Definition from OM1.1 in Ch. 8)

Definition: This field contains the first OM1 segment in a message and is described as 1, the second as 2, and so on.

(Definition from OM2.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment. Refer to Table 0648 - Units of Measure in Chapter 2C for valid values.

(Definition from OM3.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

(Definition from OM4.1 in Ch. 8)

Definition: The OM4-1 contains a numeric value that indicates a unique set of OM1, OM2, OM3, and OM4 components; each OMn-1 in a set will have the same value as illustrated in the example below. Because the OM4 segment can repeat, but needs to have a unique number for use with OM4-17, the sequence number must be appended with a sequence number as shown in the second example below.

OM4-1 Sequence Number – Test/Observation Master File Example:

MSH|...<cr>

// start MFE Test Begin group

MFE|A|...<cr>

OM1|1|...<cr>

OM2|1|...<cr>

OM3|1|...<cr>

OM4|1|...<cr>

// end MFE Test Begin group

// start MFE_Test_Begin group

MFE|A|...<cr>

OM1|2|...<cr>

OM2|2|...<cr>

OM3|2|...<cr>

OM4|2.1|...<cr>

OM4|2.2|...<cr>

//end MFE_Test_Begin group

(Definition from OM5.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

(Definition from OM6.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

(Definition from OM7.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

(Definition from OMC.1 in Ch. 8)

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

OM6-2: Derivation Rule (TX) 00657

Definition: This field is used when there are patient variables that are derived from one or more other patient variables (e.g., creatinine clearance, ideal weight, maximum daily temperature, average glucose, framingham risk). This field contains the rules for deriving the value of this variable (i.e., nature code C, as given in OM1-18 - Nature of Service/Test/Observation). These can be described in terms of humanly understandable formulas or descriptions.

When possible, however, they should be defined in terms of the Arden Syntax for specifying selection and transcendative functions and algebraic operations, ASTM E1460-92. Derivation rules that are represented in Arden Syntax should begin and end with an Arden slot delimiter (;;). Within this syntax, variables should be identified by OM1-2 - Producer's Service/Test/Observation ID. We recommend the use of the Arden Syntax because it permits the unambiguous specification of most such derived values and is a published standard for medical logic modules.