The Canonical Data Model (CDM) aims to standardise data structures across NHS England, facilitating data integration and interoperability.

It is being developed incrementally and based on real-world use cases, and will be refined and approved through specific domains and topics. This model has been shaped by input from expert reference groups and subject matter experts and is designed to enhance the flow of data from source systems, leading to improved operational and analytical insights.

The model incorporates several key features and design principles to achieve its aims, ensuring data is robust, interoperable, and consistently understood:

• domain based development
• subject of care centric
• controlled vocabularies
• metadata and CDM dictionary
• technology agnostic
• normalised structure
• consolidates data standards
• alignment with key standards
• linked to NHS master and reference data

The CDM is structured in distinct layers, each building upon the last to ensure a model that is comprehensive and can be implemented.

• NHS conceptual data model
• This layer provides a high-level, technology-agnostic blueprint of fundamental healthcare concepts.

NHS logical data model (Canonical Data Model)

• NHS conceptual data model
• This technology-neutral layer defines the detailed structure and relationships of key data entities. This model represents the merger of the Federated Data Platform (FDP) and NHS logical models.

Physical data models

• NHS conceptual data model
• These models represent the actual physical implementation of the CDM, often taking the form of specific data products.