Complex
Primitive
ActivityDefinition
CapabilityStatement
CodeSystem
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ConceptMap
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Library
List
Measure
MessageHeader
Observation
Patient
PlanDefinition
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Resource
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StructureDefinition
StructureMap
ValueSet
default
Base StructureDefinition for Timing Type
Timing
Path
Timing
Id
Timing
Cardinality
0 - *
Definition
Specifies an event that may occur multiple times. Timing schedules are used to record when things are planned, expected or requested to occur. The most common usage is in dosage instructions for medications. They are also used when planning care of various kinds, and may be used for reporting the schedule to which past regular activities were carried out.
Comment
A timing schedule can be either a list of events - intervals on which the event occurs, or a single event with repeating criteria or just repeating criteria with no actual event. When both event and a repeating specification are provided, the list of events should be understood as an interpretation of the information in the repeat structure.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Condition
ele-1
Path
Timing.event
Id
Timing.event
Type
Cardinality
0 - *
Definition
Identifies specific times when the event occurs.
Comment
Requirements
In an MAR, for instance, you need to take a general specification, and turn it into a precise specification.
Path
Timing.repeat
Id
Timing.repeat
Type
Cardinality
0 - 1
Definition
A set of rules that describe when the event is scheduled.
Comment
Requirements
Many timing schedules are determined by regular repetitions.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
tim-9 [error]
If there's an offset, there must be a when (and not C, CM, CD, CV)
tim-5 [error]
period SHALL be a non-negative value
tim-6 [error]
If there's a periodMax, there must be a period
tim-7 [error]
If there's a durationMax, there must be a duration
tim-8 [error]
If there's a countMax, there must be a count
tim-1 [error]
if there's a duration, there needs to be duration units
tim-10 [error]
If there's a timeOfDay, there cannot be be a when, or vice versa
tim-2 [error]
if there's a period, there needs to be period units
tim-4 [error]
duration SHALL be a non-negative value
Path
Timing.repeat.bounds[x]
Id
Timing.repeat.bounds[x]
Type
Cardinality
0 - 1
Definition
Either a duration for the length of the timing schedule, a range of possible length, or outer bounds for start and/or end limits of the timing schedule.
Comment
Path
Timing.repeat.bounds[x].Duration.value
Id
Duration.value
Type
Cardinality
0 - 1
Definition
The value of the measured amount. The value includes an implicit precision in the presentation of the value.
Comment
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).
Requirements
Precision is handled implicitly in almost all cases of measurement.
Path
Timing.repeat.bounds[x].Duration.comparator
Id
Duration.comparator
Type
Cardinality
0 - 1
Definition
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.
Comment
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.
Requirements
Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
Path
Timing.repeat.bounds[x].Duration.unit
Id
Duration.unit
Type
Cardinality
0 - 1
Definition
A human-readable form of the unit.
Comment
Requirements
There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
Path
Timing.repeat.bounds[x].Duration.system
Id
Duration.system
Type
Cardinality
0 - 1
Definition
The identification of the system that provides the coded form of the unit.
Comment
Requirements
Need to know the system that defines the coded form of the unit.
Condition
qty-3
Path
Timing.repeat.bounds[x].Duration.code
Id
Duration.code
Type
Cardinality
0 - 1
Definition
A computer processable form of the unit in some unit representation system.
Comment
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.
Requirements
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.
Path
Timing.repeat.count
Id
Timing.repeat.count
Type
Cardinality
0 - 1
Definition
A total count of the desired number of repetitions.
Comment
If you have both bounds and count, then this should be understood as within the bounds period, until count times happens.
Requirements
Repetitions may be limited by end time or total occurrences.
Path
Timing.repeat.countMax
Id
Timing.repeat.countMax
Type
Cardinality
0 - 1
Definition
A maximum value for the count of the desired repetitions (e.g. do something 6-8 times).
Comment
Path
Timing.repeat.duration
Id
Timing.repeat.duration
Type
Cardinality
0 - 1
Definition
How long this thing happens for when it happens.
Comment
For some events the duration is part of the definition of the event (e.g. IV infusions, where the duration is implicit in the specified quantity and rate). For others, it's part of the timing specification (e.g. exercise).
Requirements
Some activities are not instantaneous and need to be maintained for a period of time.
Path
Timing.repeat.durationMax
Id
Timing.repeat.durationMax
Type
Cardinality
0 - 1
Definition
The upper limit of how long this thing happens for when it happens.
Comment
For some events the duration is part of the definition of the event (e.g. IV infusions, where the duration is implicit in the specified quantity and rate). For others, it's part of the timing specification (e.g. exercise).
Requirements
Some activities are not instantaneous and need to be maintained for a period of time.
Path
Timing.repeat.durationUnit
Id
Timing.repeat.durationUnit
Type
Cardinality
0 - 1
Definition
The units of time for the duration, in UCUM units.
Comment
Path
Timing.repeat.frequency
Id
Timing.repeat.frequency
Type
Cardinality
0 - 1
Definition
The number of times to repeat the action within the specified period / period range (i.e. both period and periodMax provided).
Comment
Path
Timing.repeat.frequencyMax
Id
Timing.repeat.frequencyMax
Type
Cardinality
0 - 1
Definition
If present, indicates that the frequency is a range - so to repeat between [frequency] and [frequencyMax] times within the period or period range.
Comment
Path
Timing.repeat.period
Id
Timing.repeat.period
Type
Cardinality
0 - 1
Definition
Indicates the duration of time over which repetitions are to occur; e.g. to express "3 times per day", 3 would be the frequency and "1 day" would be the period.
Comment
Path
Timing.repeat.periodMax
Id
Timing.repeat.periodMax
Type
Cardinality
0 - 1
Definition
If present, indicates that the period is a range from [period] to [periodMax], allowing expressing concepts such as "do this once every 3-5 days.
Comment
Path
Timing.repeat.periodUnit
Id
Timing.repeat.periodUnit
Type
Cardinality
0 - 1
Definition
The units of time for the period in UCUM units.
Comment
Path
Timing.repeat.dayOfWeek
Id
Timing.repeat.dayOfWeek
Type
Cardinality
0 - *
Definition
If one or more days of week is provided, then the action happens only on the specified day(s).
Comment
If no days are specified, the action is assumed to happen every day as otherwise specified. The elements frequency and period cannot be used as well as dayOfWeek.
Path
Timing.repeat.timeOfDay
Id
Timing.repeat.timeOfDay
Type
Cardinality
0 - *
Definition
Specified time of day for action to take place.
Comment
When time of day is specified, it is inferred that the action happens every day (as filtered by dayofWeek) on the specified times. The elements when, frequency and period cannot be used as well as timeOfDay.
Path
Timing.repeat.when
Id
Timing.repeat.when
Type
Cardinality
0 - *
Definition
Real world events that the occurrence of the event should be tied to.
Comment
When more than one event is listed, the event is tied to the union of the specified events.
Requirements
Timings are frequently determined by occurrences such as waking, eating and sleep.
Path
Timing.repeat.offset
Id
Timing.repeat.offset
Type
Cardinality
0 - 1
Definition
The number of minutes from the event. If the event code does not indicate whether the minutes is before or after the event, then the offset is assumed to be after the event.
Comment
Path
Timing.code
Id
Timing.code
Type
Cardinality
0 - 1
Definition
A code for the timing schedule. Some codes such as BID are ubiquitous, but many institutions define their own additional codes. If a code is provided, the code is understood to be a complete statement of whatever is specified in the structured timing data, and either the code or the data may be used to interpret the Timing, with the exception that .repeat.bounds still applies over the code (and is not contained in the code).
Comment
BID etc are defined as 'at institutionally specified times'. For example, an institution may choose that BID is "always at 7am and 6pm". If it is inappropriate for this choice to be made, the code BID should not be used. Instead, a distinct organization-specific code should be used in place of the HL7-defined BID code and/or the a structured representation should be used (in this case, specifying the two event times).
Path
Timing.code.CodeableConcept.coding
Id
CodeableConcept.coding
Type
Cardinality
0 - *
Definition
A reference to a code defined by a terminology system.
Comment
Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Requirements
Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.
Path
Timing.code.CodeableConcept.coding.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
Timing.code.CodeableConcept.coding.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
Timing.code.CodeableConcept.coding.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
Timing.code.CodeableConcept.coding.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
Timing.code.CodeableConcept.coding.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.