Quantitative Relations in RIM
Contents
Discussion concerning quantitative relations in RIM
This discussion is related to the May 2010 RIM ballot reconciliation, see MnM_Minutes_CC_20100603#Comment_Grouping_.22Disambiguate_Quantity_Attributes.22. An intitial document for discussion is provided here: [1].
Target is to revise definitions of Participation.quantity, Entity.quantity and Role.quantity etc and to develop a "Matrix" of quantitative relations in RIM for inclusion in the RIM for the September 2010 ballot. This matrix will consider the various "quantity" attributes in the RIM (on one axis) and the various use cases for quantity (on the other axis), indicating clearly which of attributes are used in each and what they express.
Attribute Definitions
The following definitions try use the same language constructs to express the definitions of all the quantity attributes:
Entity.quantity
Voter Proposal
Specifies the amount of the Entity.
Used to describe the amount of the quantity itself, irrespective of potential participations of the entity as a whole or in parts.
Current RIM Definition
A physical quantity specifying the amount of the physical thing represented by the Entity object, either as a count of the members of a group, or as some other physical quantity. In order to explicitly identify a group of like entities, a static model design should constrain the PQ data type of this attribute to INT, thus providing a count of the entities in the group.
Examples: 1 human being, 2 cats, 500 cows, 20 mL of blood, 1 kg of yeast, 200 study subjects..
Usage Notes: Just as the name of a Person may change, or even its gender, the quantity of any entity can be subject to change too. With material and bulk living subjects it is possible for the quantity to gradually diminish, or, for such an Entity to be portioned out into smaller amounts of the same kind of Entity (e.g. aliquoting in a laboratory or distributing a production lot in smaller amounts.) In the case of this portioning out of an amount into smaller amounts, the initial Entity instance of the large amount may cease to exist, yet the portions may still be traceable to the initial Entity of the large amount (as in patient for a specimen aliquot or lot for a vaccine).
Specifying Entity.quantity is often not necessary as one can specify quantity in relation to other Entities (Role.quantity), participations (Participation.quantity), and and in Acts which consume or produce such Entity (e.g. SubstanceAdministration.doseQuantity, Supply.quantity).
UsageConstraint: Entity quantity should only be used for specifically identified Entities (such as the contents of beer keg #XP27-35) or in cases where the quantity is an intrinsic part of the specification of the entity (such as a specific portion of phosgene).
Formal Constraint: Quantity must be an extensive amount, that is, a count number or an additive quantity, such as mass (1 kg), volume (1 L), amount of substance (1 mol), or another quantity of a kind suitable to describe an amount (catalytic activity).
Open issue: Specifying quantity in terms of an arbitrary, procedure-defined kind of quantity (e.g., tuberculin-units) may not allow to reliably interpret such quantity statement.
Proposed Revised RIM Definition
A physical quantity specifying the amount of the physical thing represented by the Entity object, either as a count of the members of a group, or as some other physical quantity. Describes the amount of the Entity, irrespective of potential Participations of the Entity as a whole or in parts. In order to explicitly identify a group of like entities, a static model design should constrain the PQ data type of this attribute to INT, thus providing a count of the entities in the group.
Examples: 1 human being, 2 cats, 500 cows, 20 mL of blood, 1 kg of yeast, 200 study subjects..
Usage Notes: Just as the name of a Person may change, or even its gender, the quantity of any entity can be subject to change too. With material and bulk living subjects it is possible for the quantity to gradually diminish, or, for such an Entity to be portioned out into smaller amounts of the same kind of Entity (e.g. aliquoting in a laboratory or distributing a production lot in smaller amounts.) In the case of this portioning out of an amount into smaller amounts, the initial Entity instance of the large amount may cease to exist, yet the portions may still be traceable to the initial Entity of the large amount (as in patient for a specimen aliquot or lot for a vaccine).
Specifying Entity.quantity is often not necessary as one can specify quantity in relation to other Entities (Role.quantity), participations (Participation.quantity), and and in Acts which consume or produce such Entity (e.g. SubstanceAdministration.doseQuantity, Supply.quantity).
UsageConstraint: Entity quantity should only be used for specifically identified Entities (such as the contents of beer keg #XP27-35) or in cases where the quantity is an intrinsic part of the specification of the entity (such as a specific portion of phosgene).
Formal Constraint: Quantity must be an extensive amount, that is, a count number or an additive quantity, such as mass (1 kg), volume (1 L), amount of substance (1 mol), or another quantity of a kind suitable to describe an amount (catalytic activity).
Open issue: Specifying quantity in terms of an arbitrary, procedure-defined kind of quantity (e.g., tuberculin-units) may not allow to reliably interpret such quantity statement.
Role.quantity
Voter Proposal
A ratio (numerator : denominator) where the numerator specifies the amount of the Entity playing the Role and the denominator specifies the amount of the Entity scoping the Role. Thus, the ratio specifies the relative amount of the "contained" entity in the "containing" entity.
Used for Roles that represent composition relationships between the scoping and playing Entities.
Current RIM Definition
A ratio (numerator : denominator) specifying the relative quantities of the Entity playing the Role in the Entity scoping the Role, used for Roles that represent composition relationships between the scoping and playing Entities.
Examples: 1) This syrup's (scoper) ingredients include 160 mg (numerator) Acetaminophen (player) per tablespoon (denominator).
2) This herd (scoper) consists of 500 (numerator) cattle (player).
3) A VAX 6630 computer (scoper) has 3 (numerator) CPUs (player) as parts.
4) This package (scoper) contains 100 (numerator) pills (player).
Usage Notes: In composition-relationships (e.g., has-parts, has-ingredient, has-content) the Role.quantity attribute specifies that a numerator amount of the target entity is comprised by a denominator amount of the source entity of such composition-relationship. For example, if a box (source) has-content 10 eggs (target), the relationship quantity is 10:1; if 0.6 mL contain 75 mg of FeSO4 the ingredient relationship quantity is 75 mg : 0.6 mL. Both numerator and denominator must be amount quantities (extensive quantities, i.e., a count number, mass, volume, amount of substance, amount of energy, etc.).
Proposed Revised RIM Definition
A ratio (numerator : denominator) where the numerator specifies the amount of the Entity playing the Role and the denominator specifies the amount of the Entity scoping the Role. Thus, the ratio specifies the relative amount of the "contained" entity in the "containing" entity.
Examples: 1) This syrup's (scoper) ingredients include 160 mg (numerator) Acetaminophen (player) per tablespoon (denominator).
2) This herd (scoper) consists of 500 (numerator) cattle (player).
3) A VAX 6630 computer (scoper) has 3 (numerator) CPUs (player) as parts.
4) This package (scoper) contains 100 (numerator) pills (player).
Usage Constraint: Used for Roles that represent composition relationships between the scoping and playing Entities. Restrict class codes that are members of value set RoleClassPartitive (2.16.840.1.113883.1.11.10429)
Usage Notes: In composition-relationships (e.g., has-parts, has-ingredient, has-content) the Role.quantity attribute specifies that a numerator amount of the target entity is comprised by a denominator amount of the source entity of such composition-relationship. For example, if a box (source) has-content 10 eggs (target), the relationship quantity is 10:1; if 0.6 mL contain 75 mg of FeSO4 the ingredient relationship quantity is 75 mg : 0.6 mL. Both numerator and denominator must be amount quantities (extensive quantities, i.e., a count number, mass, volume, amount of substance, amount of energy, etc.).
Participation.quantity
Voter Proposal
Specifies the amount of the player Entity of the Participation's role that is used (applied, administered, consumed, provided, created..?) in the Participation's act.
Used for situations where a defined quantity of a given entity participates in an Act. Examples: Entity as a component of a recipe, to be supplied or consumed by the act or as a necessary ingredient that remains unchanged by the act.
Current RIM Definition
Specifies the amount of the player Entity of the Participation's role in the Participation's act.
Examples: Mix 10 gram of sugar with 1 teaspoon of salt in 1 liter of water uses the Participation.quantity value 10 g, 1 L, and 1 [tsp_us] specifically one each of the respective Participations while leaving the playing Entity simply with determiner = KIND and no quantity.
UsageConstraint: If an Entity quantity is also defined, the Participation.quantity overrides the Entity.quantity. This is useful if one wanted to specify several distinct Acts each of which takes a specified smaller amount from an identified batch of a material. If the Act itself has a quantity, the meaning of that quantity is unchanged. For example, Supply act quantity specifies the quantity ultimately supplied. This may be less than the quantities of the source products going into the supply (e.g., to deal with necessary waste or overages). The same holds for SubstanceAdministration.doseQuantity. This way the new Participation.quantity does not disturb the interpretation of quantities of any of the existing attributes and surrounding structures.
Quantity must be an extensive amount, that is, a count number or an additive quantity, such as mass (1 kg), volume (1 L), amount of substance (1 mol), or another quantity of a kind suitable to describe an amount (catalytic activity).
The Participation quantity can not be larger than the playing Entity quantity if the latter is finite. Especially, when the playing Entity is an individual (e.g., a single person, a single device, indicated by the Entity.quantity being 1, explicitly or implicitly) then the Participation.quantity can not be larger than 1. Also, if the Entity is of an indivisible kind (such as, again, an individual human being or a device) then the quantity can not be smaller than 1.
Rationale: The purpose of this is to specify precisely the amount of each substance (or other material) to be used in an interaction between multiple substances.
An example use is for a recipe, where specific amounts of multiple things are processed together in an act. A special case - the important one here - is when we describe a chemical reaction with Act. For example, in the reaction:
C6(H2O)6 + 6 O2 --> 6 CO2 + 6 H2O
we would specify all 4 molecules as Participations and could use the quantity attribute to place the values 1, 6, 6, and 6 respectively for the molecules.
Prior to this change would need to use the Entity.quantity attribute in each of the participants. However, since the removal of the very confusing determiner "quantified kind", we would have to have 2 Entities for each substance in the reaction: one representing the O2 molecule and one representing the group of 6 O2 molecules. While one can ignore this issue and just put only the 6 O2 molecules out there, conceptually the Entity of any amount, or 1 O2 molecule and that of 6 of these molecules would still be different. It is only a kludge to use the Entity.quantity so conveniently. However, in Participation.quantity it would be very clear.
Proposed Revised RIM Definition
Specifies the amount of the player Entity of the Participation's role that is used (applied, administered, consumed, provided, or created) in the Participation's act.
Examples: Entity as a component of a recipe, to be supplied or consumed by the act or as a necessary ingredient that remains unchanged by the act.
Usage Constraint: Used for situations where a defined quantity of a given entity participates in an Act.
UsageConstraint: If an Entity quantity is also defined, the Participation.quantity overrides the Entity.quantity. This is useful if one wanted to specify several distinct Acts each of which takes a specified smaller amount from an identified batch of a material. If the Act itself has a quantity, the meaning of that quantity is unchanged. For example, Supply act quantity specifies the quantity ultimately supplied. This may be less than the quantities of the source products going into the supply (e.g., to deal with necessary waste or overages). The same holds for SubstanceAdministration.doseQuantity. This way the new Participation.quantity does not disturb the interpretation of quantities of any of the existing attributes and surrounding structures.
Quantity must be an extensive amount, that is, a count number or an additive quantity, such as mass (1 kg), volume (1 L), amount of substance (1 mol), or another quantity of a kind suitable to describe an amount (catalytic activity).
The Participation quantity can not be larger than the playing Entity quantity if the latter is finite. Especially, when the playing Entity is an individual (e.g., a single person, a single device, indicated by the Entity.quantity being 1, explicitly or implicitly) then the Participation.quantity can not be larger than 1. Also, if the Entity is of an indivisible kind (such as, again, an individual human being or a device) then the quantity can not be smaller than 1.
Rationale: The purpose of this is to specify precisely the amount of each substance (or other material) to be used in an interaction between multiple substances.
An example use is for a recipe, where specific amounts of multiple things are processed together in an act. A special case - the important one here - is when we describe a chemical reaction with Act. For example, in the reaction:
C6(H2O)6 + 6 O2 --> 6 CO2 + 6 H2O
we would specify all 4 molecules as Participations and could use the quantity attribute to place the values 1, 6, 6, and 6 respectively for the molecules.
Prior to this change would need to use the Entity.quantity attribute in each of the participants. However, since the removal of the very confusing determiner "quantified kind", we would have to have 2 Entities for each substance in the reaction: one representing the O2 molecule and one representing the group of 6 O2 molecules. While one can ignore this issue and just put only the 6 O2 molecules out there, conceptually the Entity of any amount, or 1 O2 molecule and that of 6 of these molecules would still be different. It is only a kludge to use the Entity.quantity so conveniently. However, in Participation.quantity it would be very clear.
Supply.quantity, SubstanceAdministration.doseQuantity
Voter Proposal
Specifies the amount of the player Entity of the "product" or "consumable" Participation's role that is used (applied, administered, consumed, provided, created..?) in the act.
Used to express the quantity that is ultimately used or produced by the act, irrespective of the amount that originally participated (?).
Current RIM Definition - Supply.quantity
The amount of material that was or is to be supplied.
Usage Notes: This attribute may be used as an alternative to expectedUseTime or both may be used. If both are specified, then the specified quantity is the amount expected to be consumed within the expectedUseTime. Non-measured, but countable units such as tablet and capsule must not be specified using the unit component of the PQ data type, except as an annotation, marked by {xxx}. The type of 'countable' information is determined by information in the 'product' entity.
Design Comment: Deleted restriction on countable units.
Proposed Revised RIM Definition - Supply.quantity
Specifies the amount of the player Entity of the "product" or "consumable" Participation's role that was or is to be supplied.
Usage Notes: This attribute may be used as an alternative to expectedUseTime or both may be used. If both are specified, then the specified quantity is the amount expected to be consumed within the expectedUseTime. Non-measured, but countable units such as tablet and capsule must not be specified using the unit component of the PQ data type, except as an annotation, marked by {xxx}. The type of 'countable' information is determined by information in the 'product' entity.
Design Comment: Deleted restriction on countable units.
Current RIM Definition - SubstanceAdministration.doseQuantity
The amount of the administered substance or other substance given at one administration event.
Usage Constraint: Non-measurable, but countable units such as tablets and capsules must not be specified using the unit component of the PQ data type, except as an annotation, marked by {xxx}.
Usage Notes: The dose may be specified either as a physical quantity of active ingredient (e.g., 200 mg) or as the count of administration-units (e.g., tablets, capsules, "eaches"). Which approach is chosen depends upon the player of the 'consumable' participation (which identifies the drug being administered). If the consumable has a non-countable dosage form (e.g., measured in milligrams or litres), then the dose must be expressed in those units. If the consumable has a countable dosage form (tablets, capsules, "eaches"), then the dose must be expressed as a dimensionless count (i.e., with no other unit of measure specified). In circumstances where the administration is variable as "1 to 3 mg" the data type should be constrained to an uncertain range of PQ (URG<PQ>).
Design Comment: The constraint previously dictated that count units are not acceptable, before describing how to use them: that clause has been deleted. Question: is the constraint on the PQ data type (rather than attribute) appropriate here?
Proposed Revised RIM Definition - SubstanceAdministration.doseQuantity
Specifies the amount of the player Entity of the "product" or "consumable" Participation's role that was or is to be given at one administration event.
Usage Constraint: Non-measurable, but countable units such as tablets and capsules must not be specified using the unit component of the PQ data type, except as an annotation, marked by {xxx}.
Usage Notes: The dose may be specified either as a physical quantity of active ingredient (e.g., 200 mg) or as the count of administration-units (e.g., tablets, capsules, "eaches"). Which approach is chosen depends upon the player of the 'consumable' participation (which identifies the drug being administered). If the consumable has a non-countable dosage form (e.g., measured in milligrams or litres), then the dose must be expressed in those units. If the consumable has a countable dosage form (tablets, capsules, "eaches"), then the dose must be expressed as a dimensionless count (i.e., with no other unit of measure specified). In circumstances where the administration is variable as "1 to 3 mg" the data type should be constrained to an uncertain range of PQ (URG<PQ>).
Design Comment: The constraint previously dictated that count units are not acceptable, before describing how to use them: that clause has been deleted. Question: is the constraint on the PQ data type (rather than attribute) appropriate here?
Open issues
- Should "amount" be defined in a more formal way?
- What are the constraints on quantities and units used to express "amount"?
- are there formal constraints how to express "amount" as a PQ - e.g. for particular values of Material.formCode ?
- disambiguation between
- situations where Role represents the absolute amount of the playing entity given in Role.quantity.numerator and
- situations where Role only defines the relative amount of playing and scoping entity while the absolute amount is epressed with Participation.quantity, Supply.quantity or SubstanceAdministration.doseQuantity.
- The former disambiguation is related to using medicinal product "strength" in terms of total amount vs. relative amount.
Countable Entities
From the current RIM spec: The type of 'countable' information is determined by information in the entity (e.g. in the 'product' entity participating in a Supply Act).
Open issue:
When one of the .quantity attributes is referring to "countable entities", the unit in PQ is "1". In this situation it may not be clear what exactly is the "thing" to be counted: Is it the physical object reparesented by the entity class? Or is it a subcomponent of this object, e.g. a single tablet from a package (where the package is the entity).
Specifically for SubstanceAdministration there are some additional rules in the definition of SubstanceAdministration.administrationUnitCode. The impact of these rules and the relation to Material.formCode may not be entirely clear.
