National Diet and Nutrition Survey: Linking data

More information about data we would like to link to your survey and why it is important.

What is linking data?

During your interview we will ask for your permission to link your questionnaire answers to other administrative data, in this case your health records.

To take part in the study you do not have to give your permission to link your data at all. This is your choice and will not affect your participation otherwise.

Why is linking data important?

Linking your answers to other data will help us build a more complete picture of your life. This information allows us to look at how a person’s lifestyle can have an impact on their future health. For example, if a person who took part in the NDNS gets cancer or dies, the type of cancer or cause of death will be linked to the survey.

What data would we like to link to?

When you take part in NDNS we will ask you for consent to link to data from the following records (all held by the appropriate governing bodies):

  • England: Hospital Episodes Statistics data, civil registration mortality data ajnd Cancer Registration data (held by NHS Digital).
  • Wales: Patient Episode Database for Wales & Outpatient Activity Minimum Dataset (held by NHS Wales Informatics Service), Deaths Register (held by Office for National Statistics); Welsh Cancer Intelligence and Surveillance Data (held by Public Health Wales).
  • Scotland: Administrative health data, civil registration mortality data & Cancer Registration data (all held by Information Services Division (ISD) of NHS Scotland and National Records Scotland (NRS)).
  • Northern Ireland: Patient Administration System (held by Northern Ireland Health and Social Care Trust); civil registration mortality data (held by Northern Ireland Statistics and Research Agency (NISRA)); Northern Ireland Cancer Registry (held by Queens University Belfast and Public Health Agency).

When you take part in NDNS, you will be asked to provide consent for us to link administrative health data (as detailed above). You can choose to consent to all, some or none of them.

You will be given a consent form to read and sign, with a copy for you to keep, which explains the type of data that is collected, the purpose that it is collected for, how we control access to this information, and how to withdraw your consent if you change your mind.

How the process works

This is how the process works for NDNS:

  • To link this information we will send your name, address and date of birth to the appropriate governing bodies (see above) so they can identify your health records. Using a unique ID, your health records would subsequently be linked to the anonymised survey data.
  • We’ll separate these details from your other answers and pass them over to the government department or organisation who hold your records.
  • They’ll use your details to find your records, then they will delete the personal information that we passed to them.
  • Your records are then linked back up with your survey answers to create a new set of anonymous data to be used by researchers. This will include all the useful information from your records - but no one will know it’s about you.
  • The information will only be used for statistical and research purposes.
  • When you sign the form you are only giving us permission to link survey information to the above health records. We will in no way be able to obtain any other details from your medical records.

You can withdraw your permission to data linkage at any time.

If you do wish to withdraw your consent, please write to the National Centre for Social Research, 35 Northampton Square, London EC1V 0AX, or telephone 0800 652 4572.