www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Introduction to UCUM
Unified Code for Units of
Measure
FH-Prof. Dr. Jozef Aerts
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
UCUM Unified Code for Units of Measure
• Developed by the Regenstrief Institute (Indianapolis,
USA)
• Not a list, a system
• Example: mg/dl
•
•
•
•
•
"m" = milli (prefix)
"g" = gramm
"/" = per
"d" = deci (prefix)
"l" = liter
• Website: www.unitsofmeasure.org
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
2
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
UCUM Other valid constructs
•
•
•
•
•
•
10*9/l : billion per liter, e.g. for thrombocytes
% : percent
10*3/ul : thousand per microliter
mmol/mol : milli-moles per mole
cm[Hg] : centimeter mercury column (pressure)
m[H2O] : meter water column (pressure)
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
3
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
UCUM also non-SI units
• [ft_i] : foot
• [in_i] : inch
• [lbf_av] : pound
• Non-SI units may not be prefixed!
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
4
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
UCUM Other valid constructs
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
5
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
The ucum-essence.xml
• XML file containing all symbols used in UCUM
• And their conversion factors when not basic
• Allows to do automated conversions
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
6
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
The ucum-essence.xml
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
7
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Commonly Used UCUM Codes for
Healthcare Units
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
8
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Commonly Used UCUM Codes for
Healthcare Units
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
9
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Special remarks
• mU/g{Hgb} : milliUnits per gram Hemoglobin
• {Hgb} is NOT part of the unit! It is an "annotation"
Other common examples:
{cells}
{cre}
{specimen}
Introduction to UCUM
Unified Code for Units of Measure
{RBC}
Jozef Aerts
10
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Annotations and "bad habits"
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
11
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
LOINC and UCUM
• LOINC database contains example UCUM units
for each test
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
12
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Use of UCUM in healthcare
• Mandatory in HL7-CDA (EHRs)
• Mandatory in FDA-SPL
• Strongly encouraged by LOINC
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
13
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
UCUM usage by CDISC
• CDISC-CT team refuses usage of UCUM
• Has developed its own list (not a system)
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
14
www.fh-joanneum.at
APPLIED
COMPUTER SCIENCES
Institute for eHealth
Next part:
Use of LOINC and UCUM
in CDISC SDTM and SEND
Introduction to UCUM
Unified Code for Units of Measure
Jozef Aerts
15