DOI: 10.5255/ukda-sn-5795-5
title: Millennium Cohort Study: Third Survey, 2006
title: Millennium Cohort Study – Survey and Biomeasures Data
title: MCS3

description: &lt;i&gt;Background&lt;/i&gt;:&lt;br&gt;The Millennium Cohort Study (MCS) is a large-scale, multi-purpose longitudinal dataset providing information about babies born at the beginning of the 21st century, their progress through life, and the families who are bringing them up, for the four countries of the United Kingdom. The original objectives of the first MCS survey, as laid down in the proposal to the Economic and Social Research Council (ESRC) in March 2000, were:&lt;ul&gt;&lt;li&gt;to chart the initial conditions of social, economic and health advantages and disadvantages facing children born at the start of the 21st century, capturing information that the research community of the future will require&lt;/li&gt;&lt;li&gt;to provide a basis for comparing patterns of development with the preceding cohorts (the &lt;i&gt;National Child Development Study&lt;/i&gt;, held at the UK Data Archive under GN 33004, and the &lt;i&gt;1970 Birth Cohort Study&lt;/i&gt;, held under GN 33229)&lt;/li&gt;&lt;li&gt;to collect information on previously neglected topics, such as fathers' involvement in children's care and development&lt;/li&gt;&lt;li&gt;to focus on parents as the most immediate elements of the children's 'background', charting their experience as mothers and fathers of newborn babies in the year 2000, recording how they (and any other children in the family) adapted to the newcomer, and what their aspirations for her/his future may be&lt;/li&gt;&lt;li&gt;to emphasise intergenerational links including those back to the parents' own childhood&lt;/li&gt;&lt;li&gt;to investigate the wider social ecology of the family, including social networks, civic engagement and community facilities and services, splicing in geo-coded data when available&lt;/li&gt;&lt;/ul&gt;Additional objectives subsequently included for MCS were:&lt;ul&gt;&lt;li&gt;to provide control cases for the national evaluation of Sure Start (a government programme intended to alleviate child poverty and social exclusion)&lt;/li&gt;&lt;li&gt;to provide samples of adequate size to analyse and compare the smaller countries of the United Kingdom, and include disadvantaged areas of England&lt;/li&gt;&lt;/ul&gt;The first sweep (MCS1) interviewed both mothers and (where resident) fathers (or father-figures) of infants included in the sample when the babies were nine months old, and the second sweep (MCS2) was carried out with the same respondents when the children were three years of age. The third sweep (MCS3) was conducted in 2006, when the children were aged five years old, the fourth sweep (MCS4) in 2008, when they were seven years old, the fifth sweep (MCS5) in 2012-2013, when they were eleven years old, the sixth sweep (MCS6) in 2015, when they were fourteen years old, and the seventh sweep (MCS7) in 2018, when they were seventeen years old.&lt;br&gt;&lt;br&gt;&lt;i&gt;End User Licence versions of MCS studies&lt;/i&gt;:&lt;br&gt;The End User Licence (EUL) versions of MCS1, MCS2, MCS3, MCS4, MCS5, MCS6 and MCS7 are held under UK Data Archive SNs 4683, 5350, 5795, 6411, 7464, 8156 and 8682 respectively. The longitudinal family file is held under SN 8172.&lt;br&gt;&lt;br&gt;&lt;i&gt;Sub-sample studies&lt;/i&gt;:&lt;br&gt;Some studies based on sub-samples of MCS have also been conducted, including a study of MCS respondent mothers who had received assisted fertility treatment, conducted in 2003 (see EUL SN 5559). Also, birth registration and maternity hospital episodes for the MCS respondents are held as a separate dataset (see EUL SN 5614).&lt;br&gt;&lt;br&gt;&lt;div style=""&gt;&lt;div style=""&gt;&lt;span style="font-style: italic;"&gt;Release of Sweeps 1 to 4 to Long Format (Summer 2020)&lt;/span&gt;&lt;/div&gt;&lt;div style=""&gt;To support longitudinal research and make it easier to compare data from different time points, all data from across all sweeps is now in a consistent format. The update affects the data from sweeps 1 to 4 (from 9 months to 7 years), which are updated from the old/wide to a new/long format to match the format of data of sweeps 5 and 6 (age 11 and 14 sweeps). The old/wide formatted datasets contained one row per family with multiple variables for different respondents. The new/long formatted datasets contain one row per respondent (per parent or per cohort member) for each MCS family. Additional updates have been made to all sweeps to harmonise variable labels and enhance anonymisation. &lt;span style="font-style: italic;"&gt; &lt;/span&gt;&lt;/div&gt;&lt;/div&gt;&lt;br&gt;&lt;span style="font-style: italic;"&gt;MCS web pages&lt;/span&gt;:&lt;br&gt;Further information about the MCS can be found on the &lt;a href="https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/" target="_blank" style="background-color: rgb(255, 255, 255);"&gt;Centre for Longitudinal Studies&lt;/a&gt; web pages.&lt;br&gt;&lt;br&gt;&lt;i&gt;How to access genetic and/or bio-medical sample data from a range of longitudinal surveys:&lt;/i&gt;&lt;br&gt;A useful overview of the governance routes for applying for genetic and bio-medical sample data, which are not available through the UK Data Service, can be found at &lt;a href="http://www.metadac.ac.uk/data-access-through-metadac/" title="Governance of data and sample access" target="_blank" style="background-color: rgb(255, 255, 255);"&gt;Governance of data and sample access&lt;/a&gt; on the METADAC (Managing Ethico-social, Technical and Administrative issues in Data Access) website.&lt;br&gt;&lt;br&gt;&lt;b&gt;Secure Access datasets&lt;/b&gt;:&lt;br&gt;Secure Access versions of the MCS have more restrictive access conditions than versions available under the standard End User Licence or Special Licence (see 'Access' section below).&lt;br&gt;&lt;br&gt;Secure Access versions of the MCS include:&lt;br&gt;&lt;ul&gt;&lt;li&gt;detailed sensitive variables not available under EUL. These have been grouped thematically and are held under SN 8622 (country of birth), SN 8623 (ethnic group, religion and language), SN 8624 (health, International Classification of Diseases (ICD) codes and fertility information), SN 8625 (non-resident child information), SN 8626 (date the physical measurement was taken at sweep 3) and SN 8627 (full Standard Occupational Classification (SOC) code and number of rooms&lt;br&gt;&lt;/li&gt;&lt;li&gt;detailed geographical identifier files which are grouped by sweep held under SN 7758 (MCS1), SN 7759 (MCS2), SN 7760 (MCS3), SN 7761 (MCS4), SN 7762 (MCS5 2001 Census Boundaries), SN 7763 (MCS5 2011 Census Boundaries), SN 8231 (MCS6 2001 Census Boundaries) and SN 8232 (MCS6 2011 Census Boundaries). These files replace previously available files grouped by geography SN 7049 (Ward level), SN 7050 (Lower Super Output Area level), and SN 7051 (Output Area level)&lt;/li&gt;&lt;li&gt;linked education administrative datasets for Key Stages 1, 2 and 4 held under SN 8481 (England).  This replaces previously available datasets for Key Stage 1 (SN 6862) and Key Stage 2 (SN 7712)&lt;br&gt;&lt;/li&gt;&lt;li&gt;linked education administrative datasets for Key Stage 1 held under SN 7414 (Scotland) and SN 7415 (Wales)&lt;/li&gt;&lt;li&gt;linked NHS Patient Episode Database for Wales (PEDW) for MCS1 – MCS5 held under SN 8302&lt;/li&gt;&lt;li&gt;Banded Distances to English Grammar Schools for MCS5 held under SN 8394&lt;/li&gt;&lt;li&gt;the exact date of interview held under SN 8456&lt;/li&gt;&lt;/ul&gt;The linked education administrative datasets held under SNs 8481, 7414 and 7415 may be ordered alongside the MCS detailed geographical identifier files deposited under SNs 7758, 7759, 7760, 7761, 7762 and 7763 only if sufficient justification is provided in the application. The linked education administrative datasets are not available alongside the &lt;i&gt;Hospital of Birth: Special Licence Access&lt;/i&gt; dataset under SN 5724. Users are also only allowed one MCS5 Geographical Identifiers Census Boundaries study, either SN 7762 (2001 Census Boundaries) or SN 7763 (2011 Census Boundaries); the same applies for the MCS6 Geographical Identifiers Census Boundaries studies, users are only allowed either SN 8231 (2001 Census Boundaries) or SN 8232 (2011 Census Boundaries).&lt;br&gt;&lt;br&gt;Researchers applying for access to the Secure Access MCS datasets should indicate on their ESRC Accredited Researcher application form the EUL dataset(s) that they also wish to access (selected from the MCS Series &lt;a href="https://beta.ukdataservice.ac.uk/datacatalogue/series/series?id=2000031#!/access-data" target="_blank" style="background-color: rgb(255, 255, 255);"&gt;Access&lt;/a&gt; web page).&lt;br&gt;&lt;br&gt; &lt;p&gt;While many of the areas covered in MCS3 built on the information already collected in MCS1 (age 9 months) and MCS2 (age 3 years), a number of new items were also included, such as the measurement of waist circumference. Information was gathered from the cohort members' parents or guardians for the main Parent Interview. In addition there were four cognitive assessments and three physical measurements of the cohort child, and a paper self-completion questionnaire for up to two older siblings aged 10-15 years. The Teacher Survey and Foundation Stage Profile data and documentation are available in a separate study: SN 6847 - Millennium Cohort Study: Third Survey Teacher Survey and Foundation Stage Profile, 2006.&lt;br&gt; &lt;/p&gt; &lt;p class="x_MsoNormal"&gt;&lt;i&gt;&lt;span&gt;Update 20&lt;/span&gt;&lt;/i&gt;&lt;i&gt;&lt;sup&gt;&lt;span&gt; &lt;/span&gt;&lt;/sup&gt;&lt;/i&gt;&lt;i&gt;&lt;span&gt;March 2020: &lt;/span&gt;&lt;/i&gt;&lt;span&gt;The datasets became available in a long format (one row per respondent) compared to the wide old format (one row per family). Information on the restructure of the variables from long to wide is provided in Part 9 of the MCS 1-5 User Guide. Help with the distribution of the variables in datasets is provided in the MCS1-4_Wide_Long_Correspondence_v* and in the MCS_Longitudinal_Data_Dictionary.&lt;/span&gt;&lt;/p&gt;&lt;p&gt; May 2017: The longitudinal family file is now available separately under &lt;a href="https://discover.ukdataservice.ac.uk/Catalogue/?sn=8172" title="Millennium Cohort Study: Longitudinal Family File, 2001-2015"&gt; SN 8172&lt;/a&gt;.&lt;br&gt; &lt;/p&gt; &lt;p&gt;For the 8th edition (August 2020), the datasets are now available in the new / long format (one row per respondent). Further details are provided in Part 9 of the updated User Guide. Improvements have also been made to variable labels and details are available in the MCS Longitudinal Data Dictionary spreadsheet which provides information on all the variables available in MCS datasets across sweeps with topic information. A new Derived Variables User Guide and Data Handling Guide with Syntax in R, STATA and SPSS have also been added.&lt;br&gt;&lt;br&gt;This study now includes the data and documentation from the Teacher Survey completed at Sweep 3 which were previously available under SN 6847.&lt;br&gt;&lt;br&gt;January 2021: Users should note, a number of income and employment variables across sweeps 1-5 do not have any valid responses and are incorrectly set as "not applicable". Revised data files should be deposited in May 2021 to rectify the issue.&lt;/p&gt;