MCS Age 23 Sweep

Sweep details

Sweep status In the field
Dates September 2023 - December 2024
Age 23
Respondents Cohort members
Fieldwork agency Ipsos
Survey mode Online and face to face
Data access Data is expected to be released in late 2025 and will be available via the UK Data Service

The Age 23 Sweep involves a 60-75-minute questionnaire, which will be completed either online or face-to-face.

A broad overview of the content of the survey is provided below:

  • Family, relationships, and housing: household composition, partnerships, children and current accommodation.
  • Employment and finances: work, income, wealth (e.g. home ownership) and financial literacy.
  • Education: academic and vocational qualifications, and educational debts.
  • Health and wellbeing: physical health, mental health, health behaviours (exercise, diet, smoking, drinking, drugs), height and weight, body image.
  • Cognition: short-term memory, attention and processing speed.
  • Identity, attitudes and future aspirations: including sexual orientation and gender identity, social networks and support, political and environmental attitudes, and plans for the future.
  • Childhood circumstances and other life events: relationships in childhood, pregnancies, pregnancy outcomes and pregnancy planning.
  • Activities and risky behaviours: leisure activities, social media usage, experience of crime and gambling.
  • Cohabiting partners: topics including education, employment and income.
  • Cohort members’ own children (if applicable): child development and parenting.
  • Seeking permission to link information from routine administrative records (if not previously given) to cohort members’ study data.
  • Seeking permission to link information from children’s health and education records (for cohort members who are parents) to the study data.

The Age 23 Sweep is core-funded by the Economic and Social Research Council.


  • User guides
  • Questionnaires
  • Technical reports
  • Data notes
  • Additional
User guides

Handling missing data in the CLS cohort studies – User Guide

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 Age 23 Interview Questionnaire

MCS cohort members will complete this questionnaire for the Age 23 Sweep.

Date published: 02/11/2023
PDF: 2,38 MB


MCS Age 23 Partner Questionnaire

Partners of MCS cohort members will complete this questionnaire for the Age 23 Sweep.

Date published: 27/11/2023
PDF: 344,53 KB

Technical reports

No material of this type is available.

Data notes

No material of this type is available.


MCS8 Qualitative Research Findings

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

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL


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