A SimpleQuantity translation in G-Standard units. The extension MAY be used to additionally add translations expressed in a different unit from a different unit code system (e.g. NHG table Gebruiksvoorschriften (Table 25)).

The comparator is not used on a SimpleQuantity

A measured amount (or an amount that can potentially be measured). Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies.

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

An alternative representation of the same physical quantity expressed in a different unit from a different unit code system and possibly with a different value.

It is not necessary for information processing entities to check and enforce that the translations are valid translations of the base unit, but they are allowed to do so, and to reject instances where the translations are not valid. NOTE Translations are allowed to contain other representations in UCUM units, but there is generally no point to this as it is possible to convert from one UCUM form to another.

An Extension

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.

• value @ url

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

A SimpleQuantity translation in G-Standard units. The extension MAY be used to additionally add translations expressed in a different unit from a different unit code system (e.g. NHG table Gebruiksvoorschriften (Table 25)).

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Not allowed to be used in this context

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.

How the Quantity should be understood and represented.

Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

The comparator is not used on a SimpleQuantity

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

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.

• value @ url

An alternative representation of the same physical quantity expressed in a different unit from a different unit code system and possibly with a different value.

It is not necessary for information processing entities to check and enforce that the translations are valid translations of the base unit, but they are allowed to do so, and to reject instances where the translations are not valid. NOTE Translations are allowed to contain other representations in UCUM units, but there is generally no point to this as it is possible to convert from one UCUM form to another.

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

• value @ url

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

A SimpleQuantity translation in G-Standard units. The extension MAY be used to additionally add translations expressed in a different unit from a different unit code system (e.g. NHG table Gebruiksvoorschriften (Table 25)).

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

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.

Not allowed to be used in this context

Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

A human-readable form of the unit.

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.

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.