Represents a defined collection of entities that may be discussed or acted upon collectively but which are not expected to act collectively and are not formally or legally recognized; i.e. a collection of entities that isn't an Organization.

A unique business identifier for this group.

Allows the group to be referenced from external specifications.

Identifies the broad classification of the kind of resources the group includes.

Identifies what type of resources the group is made up of.

Group members SHALL be of the appropriate resource type (Patient for person or animal; or Practitioner, Device, Medicaiton or Substance for the other types.).

If true, indicates that the resource refers to a specific group of real individuals. If false, the group defines a set of intended individuals.

There are use-cases for groups that define specific collections of individuals, and other groups that define "types" of intended individuals. The requirements for both kinds of groups are similar, so we use a single resource, distinguished by this flag.

Indicates whether the record for the group is available for use or is merely being retained for historical purposes.

Need to be able to mark a group record as not to be used because it was created in error or is otherwise no longer available (e.g. a herd that no longer exists).

Provides a specific type of resource the group includes; e.g. "cow", "syringe", etc.

This would generally be omitted for Person resources.

A label assigned to the group for human identification and communication.

Used to identify the group in human communication.

A count of the number of resource instances that are part of the group.

Group size is a common defining characteristic.

Note that the quantity may be less than the number of members if some of the members are not active.

Identifies the traits shared by members of the group.

Needs to be a generic mechanism for identifying what individuals can be part of a group.

All the identified characteristics must be true for an entity to a member of the group.

A code that identifies the kind of trait being asserted.

Need a formal way of identifying the characteristic being described.

The value of the trait that holds (or does not hold - see 'exclude') for members of the group.

The value of the characteristic is what determines group membership.

For Range, it means members of the group have a value that falls somewhere within the specified range.

If true, indicates the characteristic is one that is NOT held by members of the group.

Sometimes group membership is determined by characteristics not possessed.

This is labeled as "Is Modifier" because applications cannot wrongly include excluded members as included or vice versa.

The period over which the characteristic is tested; e.g. the patient had an operation during the month of June.

Identifies the resource instances that are members of the group.

Often the only thing of interest about a group is "who's in it".

A reference to the entity that is a member of the group. Must be consistent with Group.type.

The period that the member was in the group, if known.

Need to track who was in a group at a particular time.

A flag to indicate that the member is no longer in the group, but previously may have been a member.

Sometimes you don't know when someone stopped being in a group, but not when.