Use of leftover blood samples and how we manage data

When a blood test occurs at a GP, antenatal appointment, outpatient clinic or blood donation there is often some blood leftover. Public Health Scotland test some of this leftover blood for antibodies to SARS-CoV-2, the new coronavirus that causes COVID-19. The detection of antibodies provides an indication that someone has had COVID-19 in the past or has developed antibodies as a result of vaccination. This provides a way of monitoring what proportion of people have had the virus and how this changes over time.

Testing approach

Where there are leftover blood samples, some will be tested. Not all samples will be tested.

The tests will not have a name associated with them and the patient will not be informed of the results.

Data handling

This data is being collected to allow PHS to understand the spread of COVID-19 in the population.

Rather than a name, the Community Health Index (CHI) number will be recorded. The CHI number will allow PHS to remove names but link the COVID-19 antibody result to other important information such as vaccination records.

The antibody result will be linked to the COVID-19 vaccination database. This will help us understand if someone had an infection or had a vaccination. The result will also be linked to hospital admissions data, which records ethnicity. This will allow us to look at how infection varies by ethnic group.

All data will be held in a secure area of Public Health Scotland. Only a limited number of staff will be able to access the data. All staff are required to complete training on Information Governance prior to accessing the data.

The Public Health Scotland Data Protection Impact Assessment (DPIA) committee and the Public Benefit and Privacy Panel for Health and Social Care (PBPP) have reviewed these plans and approved this approach. These groups are responsible for making sure your data is kept in a safe place by appropriately trained people.

Opting out

Individuals can object to the processing of your data. To opt out, please contact:

Data Protection Officer
Public Health Scotland
Gyle Square
1 South Gyle Crescent
EH12 9EB
Email address:
Telephone: 0131 275 6000

You can find more about data protection and how we handle data in our privacy notice.

Last updated: 11 September 2023