2024-11-13 - Laboratory Terminology Standards WG Meeting

Use of inheres_in for microbiology organism nucleic acid reporting 

Looked at examples of microbiology SARS-Cov2 observable entity concepts for reporting viral RNA presence in the SNOMED CT International Edition

Opinion is that the inheres_in is still superfluous and will not be relevant in a post-coordinated model of test + specimen

Farzaneh to take these back and discuss internally and decide on the use of inheres_in for these concepts

colour, appearance, identification

inheres_in  used for the property to describe the characteristic of an organism, cell or body structure - applicable to LOINC Ontology representations

Farzaneh to present examples to group at a future session

• Example 'basophils per hundred leukocytes'

• Percent property in the property hierarchy is not correct
• Property is fraction and percent is the unit

• UK modelling and proposed LOINC ontology modelling are the same (except for UK including inheres_in)

• LOINC mapping is number fraction

• Agreement from the NPU side, percent is the unit and can also be used for other property e.g. mass fraction

• Stan mentioned unit should be post-coordinated in LOINC (specified in information model)

• But cannot model 'per 100 entities' in SNOMED CT concept model so have to use the percent unit so this needs further discussion because 'per 100 cells' is more accurate representation than percent

Farzaneh to create a discussion page on the LOINC Ontology dev side for the percent vs 'per 100 cells' and feedback to the group

Karim and Andrew get some more percentage examples from UK content to look at

• There is a subhierarchy of fractions in the ratio hierarchy but subtype fractions e.g. catalytic fraction is not a subtype of catalytic ratio

In lab reporting, ratio represents:

1. Test sample against the control / normal pool

2. Different types of substances e.g. albumin/ creatinine ratio

3. substances measured by different properties e..g molar vs mass

Fraction represents:

1. measurements between the same type of substance e.g. fraction of albumin in protein

• Mass fraction and number fraction not classifying is currently causing problems in UK content - from a scientific point of view it feels like all subtypes of fractions should be subtypes of ratios

• We shouldn't expect them to subsume if they're not the same in laboratory practice

• Stan proposed we revisit after checking the resources from Young Bae and consistency with LOINC

Resources to review 

• Definitions of kinds-of-property exist in IFCC-IUPAC Silverbook https://iupac.org/what-we-do/books/silverbook/ but also on the homepage: https://labterminology.com/list-of-kinds-of-property/
• Measurement units are also superficially described on the homepage which also describes numbers (e.g. percent) as measurement units. Also a publication describes the measurement units. https://pubmed.ncbi.nlm.nih.gov/31695584/