Transcript STT AllYouWanted 02

All you wanted to know about
laboratory tests, but were afraid to ask
The informed patient
meeting the laboratory director
Metrology
Measurand 1
By Dietmar Stöckl
STT Consulting
-2-
Metrology
Without your husband?
It will be boaring he said!
We should understand
the basics, I said!
Otherwise, we may be
lost from the start.
You have a point there.
All you wanted to know about laboratory tests -2-
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VIM – The metrologist’s bible
It’s all about
measurement
International vocabulary of metrology
(VIM)
Measurand
Quantity intended to be measured
Quantity format: “System–Component
(analyte); Kind of quantity”
I knew it was
thunderstorms!
Serum–creatinine; amount-ofsubstance concentration, x µmol/L
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Measurand
S-creatinine
Alkaline picrate active
substances! (Jaffe)
Creatinine! (Enzymatic)
I knew it was
thunderstorms!
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Measurand
It's CREATININE!
Quantity intended to be
measured
NO! All clinical studies
were with Jaffe!
It's CREATININE!
eGFR: trueness-based
just introduced
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Measurand
It's CREATININE,
I type
I knew why I did'nt
want to come!
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The next visit
More about measurands
Thyroid stimulating hormone (TSH)
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Resources
ISO/IEC Guide 99:2007. International vocabulary of metrology – Basic and
general concepts and associated terms (VIM). International Organization
for Standardization: Geneva, 2007 (VIM = Vocabulaire International de
Métrologie).
JCGM 200:2008. International vocabulary of metrology – Basic and
general concepts and associated terms (VIM). International Bureau of
Weights and Measures (BIPM); Joint Committee for Guides in Metrology
(JCGM): Paris, 2008.
Freely available at:
http://www.bipm.org/en/publications/guides/vim.html
See also, Clinical and Laboratory Standards Institute (CLSI):
http://www.clsi.org/Content/NavigationMenu/Resources/HarmonizedTermin
ologyDatabase/Harmonized_Terminolo.htm
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