Census 2021 data now available inside SAIL

SAIL Databank is now accepting applications for the use of Census 2021 data, for England and Wales, from accredited researchers.

The 2021 Census of England and Wales is the largest national survey undertaken by the Office of National Statistics. Researchers will be able to apply to link Census 2021 data to the many other data sources held in SAIL.

The Census 2021 data contains:

  • Ethnicity
  • Religion
  • Country of birth
  • Disability
  • Health (self-reported)
  • Housing
  • Education
  • Employment

For the first time, the Census 2021 also contains data about sexual orientation and Armed Forces veterans.

If you would like to submit a new project application requesting access to the Census 2021 data please submit an initial enquiry via our website: Contact – SAIL Databank

To add Census 2021 data to an existing IGRP approved or RAP accredited project please contact us via helpdesk@chi.swan.ac.uk and we will advise you on the steps you need to take to gain the required approvals from both the Information Governance Review Panel and the Research Accreditation Panel.

For detailed metadata and data dictionary about the census 2021 data please visit the Health Data Research UK Innovation Gateway

About the Census

Every ten years since 1801 the nation has set aside one day for the census – a count of all people and households. It is the most complete source of information about the population that we have. The latest census was held on Sunday 21 March 2021.

Every effort is made to include everyone, and that is why the census is so important. It is the only survey which provides a detailed picture of the entire population, and is unique because it covers everyone at the same time and asks the same core questions everywhere. This makes it easy to compare different parts of the country.

The information the census provides allows central and local government, health authorities and many other organisations to target their resources more effectively and to plan housing, education, health and transport services for years to come.

In England and Wales, the census is planned and carried out by the Office for National Statistics. Elsewhere in the UK, responsibility lies with the National Records of Scotland and the Northern Ireland Statistics and Research Agency.

A usual resident is anyone who on Census Day, 21 March 2021 was in the UK and had stayed or intended to stay in the UK for a period of 12 months or more, or had a permanent UK address and was outside the UK and intended to be outside the UK for less than 12 months.

The ONS have three processes for checking and resolving duplicate responses so that the main census data should simply be one record for each person:

  1. The ONS resolve duplicates coming in for the same postcode using a process called Resolve Multiple Responses (RMR). For instance, if two people both fill in a form for their whole household, or someone from a household also submits an individual response unknown to the main submission. They have rules for checking they are duplicates, and rules for which to keep.
  2. The ONS also do an over coverage check on a sample basis for duplicates across the rest of the country, and then factor the findings into their coverage estimation calculations. This sampling focuses on the types of population which are more likely to be duplicated (people who have indicated they have a second residence on the census, students aged 18-25, armed forces personnel, children, adults enumerated at a communal establishment, etc.) but also samples from the remaining population.
  3. The ONS ask parents to fill in basic demographic information for any children who are away studying, and when they get to the question on their term-time address, if they answer that the term-time address is elsewhere, we then use that to filter those out-of-term students out of the main database. Then when that student does respond actually at their term-time address, they only include them there.