The OBX segment is documented in its entirety in Chapter 7. Its usage as it applies to Medical Records/Information Management is documented here for clarity.
Figure 9-5. OBX attributes
SEQ |
LEN |
DT |
OPT |
RP/# |
TBL# |
ITEM# |
Element Name |
1 |
4 |
SI |
R |
00569 |
Set ID- Document |
||
2 |
2 |
ID |
R |
0125 |
00570 |
Value Type |
|
3 |
80 |
CE |
O |
|
00571 |
Observation Identifier |
|
4 |
20 |
ST |
O |
00572 |
Observation Sub-Id |
||
5 |
* |
* |
C/R |
00573 |
Observation Value |
||
6 |
60 |
CE |
O |
00574 |
Units |
||
7 |
60 |
ST |
O |
00575 |
Reference Range |
||
8 |
10 |
ID |
O |
Y/5 |
0078 |
00576 |
Abnormal Flags |
9 |
5 |
NM |
O |
00577 |
Probability |
||
10 |
5 |
ID |
O |
|
0080 |
00578 |
Nature of Abnormal Test |
11 |
2 |
ID |
R/NA |
00579 |
Observation Result Status |
||
12 |
26 |
TS |
C |
00580 |
Date Last Obs Normal Values |
||
13 |
20 |
ST |
C |
00581 |
User Defined Access Checks |
||
14 |
26 |
TS |
O |
00582 |
Date/Time of Observation |
||
15 |
60 |
CE |
C |
|
00583 |
Producers ID |
|
16 |
60 |
XCN |
O |
00584 |
Responsible Observer |
||
17 |
60 |
CE |
O |
Y |
|
00936 |
Observation Method |
C = For fields OBX-12, OBX-13, and OBX-15, the field should be valued conditionally. These fields should be valued only when the result (OBX-5-observation value) contains a single concept. This is typically true when the result type is numeric, ID, or CE. When multiple medical concepts are expressed, the values of these three fields are ambiguous.* = 256 K or site negotiated
Specialized usage: Observation Identifier/Observation Sub-id have been used as optional fields that are not required in unstructured text where the nature of the document has been identified in TXA-2-document type, which is a required field, but is expressly allowed in the richer structured documentation. An example includes cases where anatomic reports may have separate OBXs for gross examination, microscopic examination, clinical impression, and final diagnosis. Another possible use includes imbedding non-textual observations within textual reports.