- UCUM is a syntax for representing units of measure for use with numerical references and values. It is not an enumerated set of codes.
- The case sensitive version is the correct unit string to be used for interoperability purposes.
- Per public comments received, there may be some limitations with UCUM in the laboratory domain that remain unresolved.
- The abbreviations used for a few of the units of measure listed in the UCUM standard are currently on lists of prohibited abbreviations from the Institute for Safe Medication Practice (ISMP).
- Some abbreviations for units of measure include symbols which may be in conflict with other HL7 standards.
- Some abbreviations for units are nonstandard for human understanding.(For example, if a result for a White Blood Cell count is 9.6 x 103/μL, the UCUM recommendation for rendering this value in a legacy character application is 9.6 x 10*3/uL. Because the “*” is a symbol for multiplication in some systems.) This recommendation may result in errors either by the information system or the human reading the result.
- Some abbreviations used in UCUM are not industry standard for the tests that use these units of measure.
- Units Of Measure Case Sensitive 2.16.840.1.113818.104.22.16839 (most frequently used codes)
- “Table of Example UCUM Codes for Electronic Messaging" published by the Regenstrief Institute, Inc. Value set is made available at http://loinc.org/usage/units and identified by the OID 22.214.171.124.4.1.12009.10.3.1