Whenever you use a health or care service, such as visiting your GP or attending hospital or using care services in the community, important information about you is collected in a patient/client record for that service. This is known as data processing for direct care purposes. Collecting this information makes sure you get the best possible care and treatment. 

If this information collected about you is shared with other organisations for purposes beyond your individual care, this is known as data processing for Secondary (indirect) care purposes. 

This means the NHS can analyse various sets of data about populations so that we can plan services and research how healthcare could be delivered in the future. 

Data from GPs, hospitals, community health services and social care might be linked to look at patterns and trends in ill health or wellbeing and used for research to improve the health of the population. The data can also be used to make sure that the right services are in the right places. 

Linked data might be used for research and development purposes such as: 

  • Understanding population level health and care needs
  • Finding cures, new treatments and therapies to improve health outcomes
  • Understanding trends in disease and care needs
  • Understanding pockets of illness or disease related to regions or communities to take preventative measures
  • Understanding the picture of carers supporting family members and what their needs are.

Or it may be used for planning and implementation: 

  • Planning for the future of health and social care

  • Evaluating health and care provision and making long-term improvements

  • As evidence for current funding and to plan for future budget rounds

  • Taking preventive action for population wide challenges such as growing obesity levels.

When we are looking at data for purposes other than your direct care we look at patterns, not individuals.

Patient records are linked by NHS number, no names, dates of birth or addresses are shared when sharing data. Council's can contribute some social care data too. 

The data is 'de-personalised'. This means your identifiers are removed so the data can't easily be linked back to you. It's not strictly ​​​​​​anonymous because someone could possibly re-identify you from a unique combination of events that happened to you.

spectrum of identifiability

Because of this, data is still kept in data ‘safe-havens’ and analysts or researchers are carefully screened before being given access. No-one can add in or take away any data except with strict controls.

People using the data sign an agreement about what they can and can’t do with it.

Read our privacy statement.

The NHS uses an opt-out scheme rather than an ‘opt-in’ approach. There are several reasons for this:

  • Although consent increases autonomy, it places a higher burden on patients
  • An opt-in system may introduce bias by only including a small portion of the population
  • Who would opt in? Who would be left out?
  • Some communities might be missing from the data.


The law requires healthcare providers to share information from patient medical records with NHS Digital or Public Health England to:

  • plan and manage services
  • check care provided is safe
  • prevent infectious diseases from spreading.

As a courtesy, the government offers patients the right to opt-out of their data being uploaded to NHS Digital.

More information on the “national data opt-out” and to register your preference.