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documentation:vocabulary:ucum [2016/06/14 09:37]
cgreich
documentation:vocabulary:ucum [2024/09/02 12:39] (current)
jcruz
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 ===== UCUM ===== ===== UCUM =====
-The Unified Code for Units of Measure ([[http://unitsofmeasure.org/ucum.html|UCUM]]) is a code system intended to include all units of measures being contemporarily used in international science, engineering,​ and business. It provides the Standard Concepts for all units in the OMOP Standardized ​Vocabulary.  +Thank you for visiting the wiki! This page has moved to https://github.com/OHDSI/​Vocabulary-v5.0/wiki/Vocab.-UCUM.
- +
-Note that UCUM is not a fixed set of Concepts with a concept_code,​ like the majority of other vocabularies. Instead, it is a system of syntax and grammar for creating any possible valid unit. We incorporated a set of units that are commonly used in medical records and drug strength descriptions. +
- +
-The basic rules are described here: +
- +
-  * All units are derived from unit atoms, which are either proper units (e.g. centimeter, inch) or arbitrary units, which depend on the method of measurement (e.g. international units). +
-  * Square brackets ("​["​ and "​]"​) depict unit atoms (e.g. [U], [drop], [yd_us] ​yard US, [tb'U] - tuberculin unit), or annotations to units that make them new unit atoms (e.g. mm[Hg]) +
-  * Curly braces ("​{"​ and "​}"​) contain annotations that are traditionally used in clinical labs (e.g. mg{creat} - mg creatinine, {RBC}/uL - red blood cells per microliter)Any annotation in curly braces can be omitted without changing the meaning of the unit. +
- +
-==== Transformation ===== +
-Since there is no fixed set of UCUM-based units, there is no transformation. All UCUM Concepts are manually curated, and additions and changes can be made on request. +
- +
-==== Concept Names ==== +
-Concept Names are the full non-abbreviated names of the unit. +
- +
-==== Concept Codes ==== +
-Concept Codes are not codes in the traditional sense of the OMOP Standardized Vocabulary, identifying a distinct semantic meaning within the source vocabulary. Instead, the Concept Codes contain the unit in UCUM notation. +
- +
-==== Standard Concepts ==== +
-All UCUM units are Standard Concepts. +
- +
-==== Concept Classes ==== +
-There are two types of Concept Classes in UCUM: Units and Canonical Units. Canonical Units are those that are derived from SI proper units.  +
- +
-==== Domains ==== +
-All UCUM Concepts are of the "​Unit"​ domain. +
- +
-==== Concept Relationships ==== +
-There are only mapping relationships from equivalent units in other vocabularies. However, these mappings are not yet comprehensive. +
- +
-==== Hierarchy ==== +
-There is no hierarchical system in UCUM units.+
documentation/vocabulary/ucum.1465897062.txt.gz · Last modified: 2016/06/14 09:37 by cgreich