# Logical Record Architecture for Health and Social Care
## Discharge Summary Release 0.02

Contents
The content of this release is not comprehensive and is not fully validated and must not be used in live system implementations.
# Domain Models
The LRA Technical Model Artefacts package contains the LRA Domain Models. A Domain Model is a domain-level realization of one or more Reference Model classes. Informally, a domain (or domain of discourse) is a particular area, sphere or field of activity, thought, study or interest defined (by implication) by the things that comprise it. The domain of the LRA comprises those aspects of health and social care within England about which information is routinely recorded and shared. More formally in predicate logic, a domain is a set of variables (or instances) to which logical quantifiers (expressed by words such as 'all', 'some' and 'no') may bind, e.g. ‘all subjects of care’, ‘some procedure’ or ‘no finding of...’ It is important to distinguish the meanings of the term ‘domain’ as generally understood in data modelling and in formal logic from the occasional and narrower use of the term within healthcare informatics to mean a particular area of interest within healthcare. The terms health care domains or clinical domains (e.g. as used BS EN ISO 13606-1:2008 Health informatics — Electronic health record communication — Part 1: Reference model - note the plural) imply this particular meaning and are synonymous in this respect. This is also one of the meanings defined for the term within the HL7 v3 Glossary. Special interest groups within HL7 such as Pharmacy, Laboratory or Patient Administration are known as “domains” and the models that support their communication requirements are called DMIMs (Domain Message Information Models). However, within the context of LRA technical modelling the term “domain” is used in its broader and more general sense and is NOT restricted to mean a particular area of interest within healthcare. To make sense of a domain (i.e. to be able to model it), abstraction is used to assert the defining qualities of the things of interest. These qualities may then be used to classify things into a manageable number of types. The qualities asserted by each type are inherited and can be applied to each and every subtype. Based on this notion, LRA Domain Models are generalised representations of the things of interest (and the relationships between them) within the LRA domain of discourse. Their purpose is to provide logical record structure definitions that are optimised for reuse in representing information consistently, independent of health or social care specialty, intervention setting, encounter type, episode type, recording practice and intended use. Domain Models are therefore in general underspecified in that they require constraining to satisfy precisely the information requirements of one or more specified areas of interest. ### ENTRY Domain Models ### ELEMENT Domain Models ### Participant Domain Models