Generated Narrative: StructureDefinition Ratio-eu-lab Name Flags Card. Type Description & Constraints Ratio 0..* Ratio A measured ratio using UCUM #xD; Slices for extension Content/Rules for all slices #xD; extension:uncertainty 0..1 decimal Standard Deviation (same units as the quantity) URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertainty #xD; extension:uncertaintyType 0..1 code Probability Distribution Type for uncertainty URL: http://hl7.org/fhir/StructureDefinition/iso21090-uncertaintyType Binding: ProbabilityDistributionType (required) #xD; numerator #xD; system 0..1 uri System that defines coded unit form Required Pattern: http://unitsofmeasure.org #xD; code 1..1 code Coded form of the unit #xD; denominator #xD; system 0..1 uri System that defines coded unit form Required Pattern: http://unitsofmeasure.org #xD; code 1..1 code Coded form of the unit #xD; Documentation for this format
This profile constrains the Ratio data type to use UCUM as the code system for units and optionally share measurement uncertainty
This profile of the Ratio data type imposes the usage of the UCUM as the code system for units and allows expressing uncertainty of measurement
Copyright HL7 Europe. Licensed under creative commons public domain (CC0 1.0).
A measured ratio (or a ratio that can potentially be measured) and uncertainty of the measurement. This profile imposes that the code system for units be UCUM.
The Ratio datatype should only be used to express a relationship of two numbers if the relationship cannot be suitably expressed using a Quantity and a common unit. Where the denominator value is known to be fixed to "1", Quantity should be used instead of Ratio.
All FHIR elements must have a @value or children
hasValue() or (children().count() > id.count())
Numerator and denominator SHALL both be present, or both are absent. If both are absent, there SHALL be some extension present
(numerator.empty() xor denominator.exists()) and (numerator.exists() or extension.exists())
(count(f:numerator) = count(f:denominator)) and ((count(f:numerator) > 0) or (count(f:extension) > 0))
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Extensions are always sliced by (at least) url
Additional content defined by implementations
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Must have either extensions or value[x], not both
exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])
Standard Deviation (same units as the quantity)
The primary measure of variance/uncertainty of the value (the square root of the sum of the squares of the differences between all data points and the mean).
standardDeviation has the same units as the quantity. It is used to normalize the data for computing the distribution function. Applications that cannot deal with probability distributions can still get an idea about the confidence level by looking at standardDeviation.
Probability Distribution Type for uncertainty
A code specifying the type of probability distribution for the uncertainty.
This is only meaningful if there is also an uncertainty extension. If there is an uncertainty extension with no type, this means that the probability distribution type is unknown. In that case, the uncertainty has the meaning of an informal guess.
Numerical value (with implicit precision)
The value of the measured amount. The value includes an implicit precision in the presentation of the value.
The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).
Precision is handled implicitly in almost all cases of measurement.
PQ.value, CO.value, MO.value, IVL.high or IVL.low depending on the value
< | <= | >= | > - how to understand the value
How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.
Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
If there is no comparator, then there is no modification of the value
This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
How the Quantity should be understood and represented.
There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
The identification of the system that provides the coded form of the unit.
Need to know the system that defines the coded form of the unit.
CO.codeSystem, PQ.translation.codeSystem
A computer processable form of the unit in some unit representation system.
The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.
Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.
PQ.code, MO.currency, PQ.translation.code