| Sweep status | Completed - data available for research use |
|---|---|
| Dates | September 2023 - December 2024 |
| Age | 23 |
| Respondents | Cohort members |
| Achieved sample | 9,735 |
| Fieldwork agency | Ipsos |
| Survey mode | Online and face-to-face |
| Data access | |
| Description |
Data from the Millennium Cohort Study Age 23 Sweep are now available to download from the UK Data Service.
Most of the Age 23 Sweep data are available from the UK Data Service under an end user licence agreement, with selected sensitive data available under secure access arrangements.
The comprehensive guide to the data from the Age 23 Sweep of the Millennium Cohort Study, carried out in 2023-24 when participants were aged 23.
Date published: 10/02/2026
PDF: 3,76 MB
This guide provides information about the mcs_longitudinal_family_file which is an important dataset of the Millennium Cohort Study (MCS). A new longitudinal cohort member file, named mcs_longitudinal_cm_file, has been introduced at individual cohort member level following the MCS data collection at age 23 (sweep 8) and is included in this version.
Version 3 updated: February 2026.
Date published: 02/09/2020
PDF: 198,29 KB
This guide describes the data linkage of health administrative records from the Hospital Episode Statistics (HES) to survey data for cohort members in the Millennium Cohort Study (MCS). User guide updated: 2025.
Date published: 07/12/2022
PDF: 387,2 KB
A user guide which provides guidance and recommendations for handling mode effects in CLS’ cohort studies through applied examples, using data from the National Child Development Study (NCDS) and Next Steps.
Date published: 26/11/2024
PDF: 2,3 MB
This user guide accompanies the datasets linking education data to the records of MCS participants based in England.
Version 3 (November 2024)
Date published: 25/11/2024
PDF: 990,4 KB
This user guide aims to describe and illustrate a straightforward approach to missing data handling, while detailing some more general considerations around missing data along the way.
Date published: 03/06/2024
PDF: 1000,62 KB
MCS cohort members completed this questionnaire for the Age 23 Sweep.
Date published: 02/11/2023
PDF: 2,8 MB
Partners of MCS cohort members completed this questionnaire for the Age 23 Sweep.
Date published: 27/11/2023
PDF: 650,62 KB
MCS cohort members completed this questionnaire for the Age 23 Sweep.
Date published: 10/02/2026
PDF: 771,25 KB
Technical report authored by Ipsos which provides all technical details regarding the design and implementation of the MCS Age 23 Sweep.
Date published: 10/02/2026
PDF: 1,95 MB
Appendices accompanying the Technical Report authored by Ipsos which provides all technical details regarding the design and implementation of the MCS Age 23 Sweep.
Date published: 10/02/2026
PDF: 5,48 MB
No material of this type is available.
The Child of the New Century (CNC) Study (also known as the Millennium Cohort Study) follows the lives of around 19,000 young people living across England, Scotland, Wales and Northern Ireland. Two stages of qualitative research were carried out to support the design of engagement approaches.
Date published: 15/09/2023
PDF: 3,45 MB
Centre for Longitudinal Studies
UCL Social Research Institute
20 Bedford Way
London WC1H 0AL
Email: clsdata@ucl.ac.uk
