Every LOINC is the chosen standard for clinical and laboratory tests and observations.
Briefly, every test/terminology in LOINC has 17 attributes. Wiki lists the following 6 six fields as unique specification of each identified single test, observation, or measurement-
- Component
- Property
- Time aspect
- System
- Scale
- Method
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Every test has a unique code/ID in the format - nnnnn-n, short name and long name.
LOINC has comprehensive guide and documentation and tools. Start here
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