Restricted fields

Fields such as home location, facial images, job code at visit as entered and date of birth are restricted in UK Biobank (UKB).   Example restricted field_ids are listed at the end of this article.   If a field is restricted, it will not be available in a UK Biobank Research Analysis Platform (UKB-RAP) project of any cost tier unless special permission has been granted.

Finding restricted fields

Restricted fields are marked as # in UKB Showcase field lists, and say “This information is regarded as restricted …” on the UKB Showcase field page

For example, Category 100094 holds 6 data fields, including field 33 which is restricted.

Requesting access 

To request access to a restricted field, researchers should contact the UKB Access team by submitting a ticket in the UK Biobank Community website.  To avoid unnecessary delay, please include full details as described below.  

For Covid-19 vaccination fields or for geographical fields such as home locations the Principal Investigator (PI) of the AMS application should submit the request.

For a few restricted fields, such as field 132 which is scheduled for removal, permission will not be granted at all.  Field 20277 is an unrestricted alternative to field 132.   Some phased restricted fields are temporarily restricted, and will only be available when the restriction is removed.   For the majority of restricted fields, permission may be granted if the proposed use of the field is within the scope of the AMS application and is for health-related research in the public interest.   This will be assessed by the UKB Epidemiology team.   Permission will not be granted if there are unrestricted alternatives that should be sufficient.   For example, the date of birth in field 33 is restricted.  Most researchers are expected to use a combination of year of birth in field 34 and month of birth in field 52.   Any request for field 33 should include an explanation of why year and month are not sufficient.

Derived data from particularly sensitive fields

For restricted fields that are particularly sensitive, such as date of birth or 100m grid home locations, permission is not granted directly.   Permitted research groups are provided with a separate project inside their UKB-RAP application, containing a different set of EIDs, the restricted fields, and a set of data fields that are deemed essential for creating derived fields.   Researchers derive the fields they need.  UKB map the derived fields back to the original project EIDs and provide the rebadged data in the dedicated project, once the restricted data has been deleted.   For example, an application to investigate the effects of fine particulate matter might request 100m grid locations and use it to generate a derived field stating  the particulate matter level for each participant.   There will be a negligible cost for storing the file containing the derived fields.   The process will entail delay. 

Particularly sensitive fields requiring a separate project and derived fields include the following:

Requests for particularly sensitive restricted fields should include a description of the proposed derived fields, together with a justification of the value of the research and an explanation of how it relates to the scope of the application.

Covid-19 research

Record-table field 32040 COVID-19 vaccination records and derived tabular field 32041 When COVID19 vaccinations administered have been provided by national NHS data sources for Covid-19 research only.   When requesting these Covid-19 vaccination fields, the PI should explicitly confirm that they will ensure that this data will only be used for Covid-19 research.

Home location data

Participant addresses are not held in the main UKB database and are not available to any researchers in any circumstances.   Home location data fields have been created from participant address data.   For more details, see the category descriptions and the resources associated with each field in Showcase, such as  Category 150 , Category 100024  and Resource 2060 . 

Researchers who only require a very general idea of location, such as “Wales” or “London”, may find that instance 0 of field 54 UK Biobank assessment centre is sufficient.   At the baseline visit instance 0 each participant was invited to an assessment centre within 30 miles of their home.   This is not true for the imaging visits instance 2 and 3, where the distance from home address to centre location can be much greater.

There are four sets of home location fields.

     1km grid

100m grid (particularly sensitive)

Output area (particularly sensitive)

Admin or super area

Research groups will not be granted both grid fields and area fields in the same AMS application, because of potential risk of identification within overlap regions.   Research groups will not be granted fields from any two different home location sets simultaneously.   It is possible to receive 32223/4 (1km grid) together with 22702/4 (1km grid).   It is not possible to receive 32223/4 together with 20271.   It is not possible to receive 32223/4 simultaneously with 32221/2.   For this reason, we ask the PI to confirm any request for home location fields.

Updated grid fields

Fields 22702/4 are being replaced by fields 32223/4.   Fields 22701/3 are being replaced by fields 32221/2.   For more details, please see the article “Replacement of Category 150 location history fields”  which is available from the UKB community forum.

Researchers are encouraged to wait for fields 32223/4, which will be available in UKB-RAP version 19.  The UKB-RAP version 19 update is scheduled to happen in the first half of 2025.   The current UKB-RAP version can be seen here.   Researchers with a tight timeline may request fields 22702/4, if they confirm that they understand the limitations of these fields.   Fields 22702/4 will be available for dispense to new UKB-RAP projects during UKB-RAP versions 18 and 19, but will be unavailable for dispense to new projects during UKB-RAP version 20 onwards.   Once dispensed, the fields will continue to be available within that UKB-RAP project until deletion of the project or expiry of the AMS application.   It is acceptable to request both old 22702/4 and new 32223/4.

Assessment visit or history

Fields 22688/9 and 22686/7 contain only the grid locations for the addresses that were correct at the time of a UKB assessment centre visit.   For most participants (~80%) this is a single grid location for the home address that was correct at the baseline visit instance 0.  

Fields 22702/4, 22701/3, 32221/2 and 32223/4 include the grid locations for the addresses that were correct at the time of a UKB assessment centre visit, and also the grid locations for any later participant addresses where these have been notified to UKB.  In general, there is no need to request 22688/9 as well as 32223/4 or 22702/4, as they will not provide any extra data, but it is acceptable to request 22688/9, 32223/4 and 22702/4.

Similarly, fields 28170 - 28178 are convenient subsets of grid location data that is relevant to the participants in the serology study.  They do not provide any extra data compared with 32221 - 32224.

Dispense a new UKB-RAP project

When access to a restricted field has been granted, and you have been notified of this, please create a new UKB-RAP project and dispense data to it to receive the restricted fields.

The restricted fields will only be available for processing within the UKB-RAP.   It is no longer permissible to download these fields.    If a researcher has previously been using basket downloads, and makes a new request to access any of the restricted fields, they will need to start using the UKB-RAP.

Example restricted fields

When researchers request access to any of these restricted fields, the request ticket should include the researcher's AMS application_id, the field_ids of the restricted fields being requested, and a justification of the need for the restricted data.   For some requests (see text above) the request should come from the PI.    When requesting Covid-19 vaccination fields, the PI should explicitly confirm that they will ensure that this data will only be used for Covid-19 research.