ALTERNATIVE - Discussion
Where a concept within a particular SNOMED product is MOVED_TO some other product, an ALTERNATIVE association can be asserted within the donor product in order to identify one or more possible active concept(s) also still active and within the same donor product that may stand in for the moved/inactivated concept.
The identified ALTERNATIVE substitute(s) are offered as semantically "sufficiently similar" to the original inactive concept, for certain unspecified use cases.
They may or may not be semantically identical to that moved, inactivated concept.
Semantically, therefore, ALTERNATIVE combines some mixture of REPLACED_BY and POSSIBLY_EQUIVALENT_TO.
For example, in the case of:
271328003 [D]Coma and stupor (situation) ALTERNATIVE 371632003 Coma (disorder)
271328003 [D]Coma and stupor (situation) ALTERNATIVE 89458003 Stupor (finding)
..the same semantics could reasonably be also expressed as two POSSIBLY_EQUIVALENT_TO associations, whereas in
206959002 [D]Lump on head (situation) ALTERNATIVE 432525007 Mass of head (finding)
207169001 [D]Retention of urine unspecified (situation) ALTERNATIVE 267064002 Retention of urine (disorder)
..usage appears much closer to either REPLACED_BY or even SAME_AS.
Historical Use
Historically, to July 2019, there had only ever been 181 uses of the ALTERNATIVE association in the International Edition, and all were in fact declared within a single release: the July 2009 International Edition.
In all 181 cases the inactive concept was also assigned a MOVED_TO association pointing at 370137002 Extension Namespace {1000000} (namespace concept), which is the namespace used by the UK NRC Clinical Extension.
By 2019, 5 of these 181 ALTERNATIVE associations had in fact themselves been withdrawn/declared inactive - usually when the association target was itself inactivated.
Combinatorial Logic
Whenever an already stated ALTERNATIVE target itself also becomes inactive - whether at the same release or later - the combinatorial logic of associations should be:
(A) ALTERNATIVE (B) and (B) SAME_AS (C) implies (A) ALTERNATIVE (C)
(A) ALTERNATIVE (B) and (B) REPLACED_BY (C) implies (A) REPLACED_BY (C)
(AIntEd) ALTERNATIVE (BIntEd) and (BIntEd) MOVED_TO (CNRC) implies (AIntEd) MOVED_TO (CNRC)
(AIntEd) ALTERNATIVE (BIntEd) and (CNRC) MOVED_FROM (BIntEd) implies (AIntEd) ALTERNATIVE (CNRC)
(A) ALTERNATIVE (B) and (B) POSSIBLY_EQUIVALENT_TO (C, D) implies (A) ALTERNATIVE (C, D)
(A) ALTERNATIVE (B) and (B) WAS_A (C AND D) implies (A) WAS_A (C AND D)
Sample Data
All 176 ALTERNATIVE associations that were still current by the July 2019 release of the International Edition are shown below.
Where a single inactive concept has more than one ALTERNATIVE association, they are listed together and appear in bold text:
INACTIVE CONCEPT (MOVED TO UK) |
| ALTERNATIVE CONCEPT BUT IN INTERNATIONAL EDITION |
206734000 [D]Convulsions, infantile (situation) | ALTERNATIVE | 87476004 Convulsions in the newborn (disorder) |
206737007 [D]Other specified convulsion (situation) | ALTERNATIVE | 91175000 Seizure (finding) |
206744003 [D]Acute vertigo (situation) | ALTERNATIVE | 399153001 Vertigo (finding) |
206747005 [D]Sleep disturbance, unspecified (situation) | ALTERNATIVE | 44186003 Dyssomnia (disorder) |
206753005 [D]Sleep rhythm irregular (situation) | ALTERNATIVE | 271793004 Irregular sleep-wake pattern (disorder) |
206770002 [D]Postviral (asthenic) syndrome (situation) | ALTERNATIVE | 266226000 Postviral infection debility (disorder) |
206770002 [D]Postviral (asthenic) syndrome (situation) | ALTERNATIVE | 51771007 Postviral fatigue syndrome (disorder) |
206783001 [D]Other general symptoms (situation) | ALTERNATIVE | 267022002 General symptom (finding) |
206787000 [D]Hypothermia, of non-environmental cause (situation) | ALTERNATIVE | 386689009 Hypothermia (finding) |
206794002 [D]Physical violence (situation) | ALTERNATIVE | 442084003 Victim of physical violence (finding) |
206801005 [D]Nervous and musculoskeletal symptoms (situation) | ALTERNATIVE | 267070008 Nervous system symptoms (finding) |
206801005 [D]Nervous and musculoskeletal symptoms (situation) | ALTERNATIVE | 440574002 Abnormal response to nerve stimulation (finding) |
206734000 [D]Convulsions, infantile (situation) | ALTERNATIVE | 87476004 Convulsions in the newborn (disorder) |
206737007 [D]Other specified convulsion (situation) | ALTERNATIVE | 91175000 Seizure (finding) |
206814006 [D]Parosmia (situation) | ALTERNATIVE | 112105008 Sense of smell altered (finding) |
206840000 [D]Other nervous and musculoskeletal symptoms (situation) | ALTERNATIVE | 267070008 Nervous system symptoms (finding) |
206847002 [D]Symptoms affecting skin and other integumentary tissue (situation) | ALTERNATIVE | 271804005 Symptom of skin and integumentary tissue (finding) |
206852007 [D]Pricking of skin (situation) | ALTERNATIVE | 162248005 Prickling sensation of skin (finding) |
206860008 [D]Rash and other nonspecific skin eruption (situation) | ALTERNATIVE | 271807003 Eruption of skin (disorder) |
206865003 [D]Local superficial swelling, mass or lump (situation) | ALTERNATIVE | 276438008 Swelling / lump finding (finding) |
206866002 [D]Swelling, local and superficial (situation) | ALTERNATIVE | 441804001 Superficial swelling (finding) |