Subject of Care Index

The Subject of Care Index is a national service being developed as part of NHS Data Architecture. 

In this context, a 'subject of care' means a person who receives health or care services. 

The Subject of Care Index helps identify when information held in different systems relates to the same person. This makes it easier to bring that information together and use it consistently, helping organisations build a more complete understanding of an individual's health and care journey. 

The Subject of Care Index brings together information about an individual, creating a trusted and consistent view that can be used across authorised services and activities. 

The Subject of Care Index works alongside existing national services, standards and identifiers, helping organisations use them more consistently and effectively across health and care. 

For example, it works alongside the Personal Demographics Service (PDS), the national service that manages core demographic information such as a person's name, address and NHS number. While PDS provides core information demographic information about an individual, the Subject of Care Index helps connect that information. 

It helps to: 

• identify when records from different systems relate to the same person 
• connect information held across multiple organisations and services 
• improve the consistency and quality of person identification 
• support the integration and consolidation of information  
• enable information to be linked safely and appropriately for authorised purposes 
• reduce duplication and fragmentation

Health and care organisations do not always hold the same information about the same person. 

For example: 

• demographic information may differ between systems 
• updates made in one organisation may not be reflected elsewhere 
• records relating to the same person may contain inconsistencies or gaps 
• different organisations may have different views of the same individual 

These differences can reduce confidence in how information is understood and used across services. 

The Subject of Care Index helps address this challenge by identifying where discrepancies exist and providing a more consistent view of information about an individual. This creates opportunities to improve the quality, completeness and consistency of information held across health and care systems. 

The Subject of Care Index also helps address challenges in analytics, research and service planning. 

Information used for these purposes is often collected from multiple organisations, systems and datasets. Without a trusted way to identify records relating to the same person, it can be difficult to build a complete and consistent understanding of people’s healthcare journeys and populations health.

The Subject of Care Index is one of the foundational components of NHS Data Architecture. NHS Data Architecture provides a consistent approach to how health and care data is structured, managed, understood and used across the NHS. 

The Subject of Care Index works alongside other NHS Data Architecture components. 

For example: 

• the NHS CDM provides a common way of describing and structuring health and care data 
• metadata and reference data help ensure information is understood, described and used consistently 
• these components support the Subject of Care Index by providing the structure, context and consistency needed for information to be connected and used effectively 

Together, these components provide a more consistent foundation for interoperability, analytics, services and future data capabilities across health and care. 

The Subject of Care Index complements the NHS CDM by helping ensure that information represented using common data structures can also be connected to the correct individual across different organisations and systems.