Example 1: Mixed ambiguity
| Concept |
|---|
| t | 200417002|Breast engorgement in pregnancy, the puerperium or lactation unspecified (finding)| |
|---|
|
has three possible meanings
Resolution:
- Create 3 new concepts:
| Concept |
|---|
| t | xxxxxxxx|Breast engorgement in pregnancy (finding)| |
|---|
|
| Concept |
|---|
| t | yyyyyyyy|Breast engorgement in the puerperium (finding)| |
|---|
|
| Concept |
|---|
| t | zzzzzzzz|Breast engorgement during unspecified period of lactation (finding)| |
|---|
|
- Inactivate
| Concept |
|---|
| t | 200417002|Breast engorgement in pregnancy, the puerperium or lactation unspecified (finding)| |
|---|
|
- POSSIBLY_EQUIVALENT_TO xxxxxxxx Breast engorgement in pregnancy (finding)
- POSSIBLY_EQUIVALENT_TO yyyyyyyy Breast engorgement in the puerperium (finding)
- POSSIBLY_EQUIVALENT_TO zzzzzzzz Breast engorgement unspecified period of lactation (finding)
- Now resolve the deprecated "unspecified" concept:
- inactivate
| Concept |
|---|
| t | zzzzzzzz|Breast engorgement during unspecified period of lactation (finding)| |
|---|
|
- SAME_AS
| Concept |
|---|
| t | 49746001|Engorgement of breasts (finding)| |
|---|
|
Example 2: Mixed ambiguity with a conjunction:
| Concept |
|---|
| t | 199779004 |Persistent occipitoposterior or occipitoanterior position - delivered (disorder)| |
|---|
|
has 2 possible meanings, neither of which already existed in SNOMED CT at the time of writing, in 2021.
The original meaning of this code dates back to ICD9: it is closely related to D660.3 DEEP TRANSVERSE ARREST AND PERSISTENT OCCIPITOPOSTERIOR POSITION DURING LABOR AND DELIVERY, a subtype within ICD9 of D660 OBSTRUCTED LABOR. This implicit meaning as a form of obstructed labor was also originally also reflected in SNOMED by its classification (back in 2002) as a subtype of | Concept |
|---|
| t | 199746004|Obstructed labor (finding)| |
|---|
|
. From this archaeology, it becomes clearer that the "persistent" adjective in the term relates in fact only to the "occipitoposterior presentation" permutation; an occipitoanterior presentation of the fetal head is the normal state of affairs in labour, and so would not usually be labelled as "persistent". That labour was obstructed, whichever the presentation, is unstated within the original SNOMED and ICD terms but was implicit from the original taxonomy in both ICD and later also in SNOMED.
This leads to the following two possible meanings:
- POSSIBLY_EQUIVALENT_TO xxxxxxxx Obstructed labour despite occipitoanterior presentation and now delivered
- POSSIBLY_EQUIVALENT_TO yyyyyyyy Obstructed labour due to persistent occipitoposterior presentation and now delivered
- However, both of these are compound clinical statements that should not be added as active concepts but are required in order to satisfy the requirement to ensure clinically safe reporting of historical data.
- In addition, it is necessary to resolve the conjunction that arises from the original concept.
Resolution:
- Create 2 new concepts:
-
| Concept |
|---|
| t | xxxxxxxx|Obstructed labour despite occipitoanterior presentation and now delivered (finding)| |
|---|
|
-
| Concept |
|---|
| t | yyyyyyyy|Obstructed labour due to persistent occipitoposterior presentation and now delivered| |
|---|
|
Inactivate
| Concept |
|---|
| t | 199779004 |Persistent occipitoposterior or occipitoanterior position - delivered (disorder)| |
|---|
|
- POSSIBLY_EQUIVALENT_TO xxxxxxxx Obstructed labour despite occipitoanterior presentation and now delivered (disorder)
- POSSIBLY_EQUIVALENT_TO yyyyyyyy Obstructed labour due to persistent occipitoposterior presentation and now delivered (disorder)
- Now resolve the 2 conjunctions:
- Inactivate
| Concept |
|---|
| t | xxxxxxxx|Obstructed labour despite occipitoanterior presentation and now delivered (finding)| |
|---|
|
as a Classification concept- EQUIVALENT_TO
| Concept |
|---|
| t | 199746004 |Obstructed labour (finding)| |
|---|
|
- EQUIVALENT_TO
| Concept |
|---|
| t | 37235006 |Occipitoposterior position (finding)| |
|---|
|
- EQUIVALENT_TO
| Concept |
|---|
| t | 236973005 |Delivery procedure (procedure)| |
|---|
|
- EQUIVALENT_TO
| Concept |
|---|
| t | 289256000|Mother delivered (finding)| |
|---|
|
- inactivate
| Concept |
|---|
| t | yyyyyyyy|Obstructed labour due to persistent occipitoposterior presentation and now delivered| |
|---|
|
as a Classification concept- EQUIVALENT_TO
| Concept |
|---|
| t | 31041000119106|Obstructed labour due to deep transverse arrest and persistent occipitoposterior position| |
|---|
|
- EQUIVALENT_TO
| Concept |
|---|
| t | 236973005 |Delivery procedure (procedure)| |
|---|
|
- EQUIVALENT_TO
| Concept |
|---|
| t | 289256000|Mother delivered (finding)| |
|---|
|