Cohort validation pack

MCS

Millennium Cohort Study

Generated 6 Oct 2026, 10:36 · ID 18

Unverified

Instructions for reviewers

Review each field against your knowledge of this cohort. Mark Accurate if the value is right, Needs correction if it is wrong or inaccurate (add notes), Not sure if you cannot verify it, or Does not apply if the field is not relevant.
Evidence shown is from our source registry. Fields marked No source yet hold values we could not yet pin to a document — those were AI-inferred and need your input most. Fields marked Searched — not published are ones we looked for and could not find publicly; the note lists where we checked.
Your selections and notes are kept in this browser tab only (not sent to the database). Print or save as PDF when finished, then return it to the DIGIT team.

Overview

Total fields

Field-cited

Whole-record source only

AI-inferred, no source yet

Searched — not published

No value held

Needs review

Source coverage

Summary of how well fields in this pack are linked to evidence.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Field-level source coverage Optional	42 of 70 reviewable fields are cited to a source (60%) · 7 with no source yet · 21 searched — not published · 26 with no value held	Computed	No citation linked to this field yet.	Response for Field-level source coverageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Identity and ownership

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Short name Required	MCS	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Page heading “Millennium Cohort Study” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Short nameAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Full name Required	Millennium Cohort Study	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Page heading “Millennium Cohort Study” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Full nameAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Managing organisation Recommended	UCL Centre for Longitudinal Studies	Field-cited	HRA — Millennium Cohort Study summary https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/millennium-cohort-study/ Section: Research summary “The study is carried out by the Centre for Longitudinal Studies at the Institute of Education, University of London.” Page: https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/millennium-cohort-study/	Response for Managing organisationAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Primary site Recommended	No value held	Not published	Searched — not published UNSOURCEABLE as single lead site assignment: MCS is managed centrally by CLS with UK-wide participant coverage and no single DIGIT site mapping published.	Response for Primary siteAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Website URL Recommended	https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Browser address “https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Website URLAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Catalogue of Mental Health Measures URL Recommended	https://www.cataloguementalhealth.ac.uk/MCS	Field-cited	Catalogue of Mental Health Measures https://www.cataloguementalhealth.ac.uk Section: Official sitemap study URL “https://www.cataloguementalhealth.ac.uk/MCS” Page: https://www.cataloguementalhealth.ac.uk/MCS	Response for Catalogue of Mental Health Measures URLAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Contact name Recommended	No value held	Not published	Searched — not published UNSOURCEABLE as single cohort contact: page lists PI and general mailbox but no designated database contact_name field owner.	Response for Contact nameAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Contact email Recommended	No value held	Not published	Searched — not published UNSOURCEABLE for direct cohort contact_email: only general mailbox (clsdata@ucl.ac.uk) and PI email are published, no dedicated cohort access contact for this field semantics.	Response for Contact emailAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Summary and status

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Description Required	UK longitudinal birth cohort following around 19,000 young people born in 2000-02 across England, Scotland, Wales and Northern Ireland, with repeated survey sweeps from infancy into adulthood.	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro “The Millennium Cohort Study (MCS) is a UK longitudinal birth study. It is following the lives of around 19,000 young people born across England, Scotland, Wales and Northern Ireland in 2000-02.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for DescriptionAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Total N Required	18,827	Field-cited	PubMed abstract — MCS cohort profile https://pubmed.ncbi.nlm.nih.gov/24550246/ Section: Abstract “18 552 families (18 827 children) were recruited to the cohort in the first sweep.” Page: https://pubmed.ncbi.nlm.nih.gov/24550246/	Response for Total NAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Total N qualifier Recommended	approximate	Field-cited	PubMed abstract — MCS cohort profile https://pubmed.ncbi.nlm.nih.gov/24550246/ Section: Abstract “18 552 families (18 827 children) were recruited to the cohort in the first sweep.” Page: https://pubmed.ncbi.nlm.nih.gov/24550246/ Value is historic recruitment count and no exact current census published on the same page -> qualifier set to approximate.	Response for Total N qualifierAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Year established Recommended	2000	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro “born across England, Scotland, Wales and Northern Ireland in 2000-02.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Cohort established in the first recruitment year 2000.	Response for Year establishedAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Active cohort Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Current updates “Millennium Cohort Study Age 23 data now available” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Active cohortAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Ongoing recruitment Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Study type “following the lives of around 19,000 young people born ... in 2000-02” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Birth recruitment cohort completed; ongoing follow-up but not open birth recruitment -> FALSE.	Response for Ongoing recruitmentAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Refreshed cohort Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Sweeps “Data are available from eight main sweeps of MCS.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Refreshed cohortAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Recontact success rate Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no cohort-wide published recontact success percentage found across reviewed CLS/HRA/PubMed sources.	Response for Recontact success rateAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Retention rate Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no single retention_rate metric published in reviewed sources for current wave.	Response for Retention rateAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Published references Recommended	doi:10.1093/ije/dyu001, doi:10.14301/llcs.v7i4.410	Field-cited	Connelly and Platt — Cohort Profile: UK Millennium Cohort Study (IJE 2014) https://doi.org/10.1093/ije/dyu001 Section: Citation “https://doi.org/10.1093/ije/dyu001” Page: https://academic.oup.com/ije/article/43/6/1719/703283 CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: About MCS “Joshi, H. and Fitzsimons, E. (2016).” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Second profile citation retained in published_references array (DOI 10.14301/llcs.v7i4.410).	Response for Published referencesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Notes Recommended	National MCS resource with multi-wave follow-up, linked administrative health/education records, and genetic/biological sample access via CLS data governance pathways.	Field-cited	HDRUK Innovation Gateway https://healthdatagateway.org Section: HDRUK collection check “UK Longitudinal Linkage Collaboration ... Millennium Cohort Study Dataset” Page: https://healthdatagateway.org/collection/98 HDRUK source category covered; entry confirms dataset presence but no additional diagnosis/site join rows beyond current cohort mapping. ClinicalTrials.gov https://clinicaltrials.gov Section: Registry search “ClinicalTrials.gov search shell retrieved for term Millennium Cohort Study” Page: https://clinicaltrials.gov/search?term=Millennium%20Cohort%20Study Registry checked per playbook Phase B; no cohort recruitment-site rows identified for MCS in this pass. ISRCTN https://isrctn.com Section: Registry search “Please enable cookies and JavaScript to use ISRCTN.” Page: https://www.isrctn.com/search?q=Millennium+Cohort+Study ISRCTN checked per playbook Phase B; static capture blocked by client-side gating, no additional cohort-site rows evidenced in accessible output. CLS — Data access https://cls.ucl.ac.uk/data-access-training/data-access/ Section: Data access “Most CLS research data are publicly available through public repositories, primarily the UK Data Service.” Page: https://cls.ucl.ac.uk/data-access-training/data-access/	Response for NotesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

3D cohort mapping

Consent, characterisation, and data availability axes used on the cohort map.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Consent level (axis) Required	3 — Broad consent (recontactable for future studies)	Field-cited	HRA — Millennium Cohort Study summary https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/millennium-cohort-study/ Section: Research summary “This application seeks REC approval for the ongoing work of the study over the next five years. This work involves 1) Keeping in touch with and tracing cohort members” Page: https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/millennium-cohort-study/ Step 1 identifiable=YES (tracking cohort members). Step 2 S251/CAG model=NO (consented longitudinal cohort). Step 3 recontactable=YES (keeping in touch and tracing). Step 4 explicit interventional randomisation consent not evidenced. -> consent_level 3.	Response for Consent level (axis)AccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Characterisation depth (axis) Required	3 — Multi-domain MH characterisation	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro + sweeps “It has tracked measures such as physical, socio-emotional, cognitive and behavioural development... Data are available from eight main sweeps of MCS.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Step 1 validated MH instruments present across sweeps. Step 2 multi-domain phenotyping present (cognitive, physical, behavioural, social). Step 3 no explicit SCID/MINI + refreshed evidence combination for level 4. -> characterisation_depth 3.	Response for Characterisation depth (axis)AccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Data availability (axis) Required	3 — Adds biological specimens/molecular data	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Data + special data “Most MCS data are available for free via the UK Data Service [SN 2000031].” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ DERIVED: hasResearch=TRUE (questionnaire/cognitive/linked records), hasBiological=TRUE (biosamples+genomics), hasAdvanced=FALSE (no imaging/wearable/digital phenotyping evidence). Formula -> 3.	Response for Data availability (axis)AccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Cohort map group (derived) Recommended	Group 2	Internal	Internal catalogue field	—	—
Population type Recommended	General population	Not published	DIGIT Cohort Portfolio Review — population type and engagement classification (Aug 2026) Classified general_population in the DIGIT cohort portfolio review (Aug 2026). Nationally representative birth cohort.	Response for Population typeAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Industry engagement status Recommended	Unknown	Not published	Searched — not published UNSOURCEABLE: industry engagement status is an organisational property of the custodian and is not publicly documented; default 'unknown' pending a cohort-owner meeting.	Response for Industry engagement statusAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Parent cohort / programme Recommended	No value held	No source yet	No citation linked to this field yet.	Response for Parent cohort / programmeAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
TWiCs eligible Recommended	No	Not published	DERIVED FALSE: no explicit interventional randomisation consent framework evidenced in reviewed sources; does not meet twics_eligible criteria from data dictionary.	Response for TWiCs eligibleAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Data modalities

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Questionnaire / interview Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro “It has tracked measures such as physical, socio-emotional, cognitive and behavioural development” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ TRUE under data-dictionary rules: validated behavioural/mental health questionnaires are repeatedly collected.	Response for Questionnaire / interviewAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Cognitive testing Recommended	Yes	Field-cited	PubMed abstract — MCS cohort profile https://pubmed.ncbi.nlm.nih.gov/24550246/ Section: Abstract “A range of health-related data have been collected as well as measures concerning ... cognitive ability” Page: https://pubmed.ncbi.nlm.nih.gov/24550246/	Response for Cognitive testingAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Physical measures Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro “It has tracked measures such as physical, socio-emotional, cognitive and behavioural development” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Evidence does not explicitly confirm objective biometrics collection on this page; conservative FALSE per dictionary TRUE-when rule.	Response for Physical measuresAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Biosamples Recommended	Yes	Field-cited	CLS — Genetic data and biological samples https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/ Section: Stored samples “The following stored biological samples are available for application ... saliva (Next Steps and MCS).” Page: https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/	Response for BiosamplesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Genomic data Recommended	Yes	Field-cited	CLS — Genetic data and biological samples https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/ Section: MCS row “MCS (born 2000-02) ... Data type ... Genetic, exome” Page: https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/	Response for Genomic dataAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Omics Recommended	No	Field-cited	CLS — Genetic data and biological samples https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/ Section: MCS row “Data type ... Genetic, exome” Page: https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/ No non-genomic omics modality listed for MCS on this page -> FALSE.	Response for OmicsAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Imaging Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Special data links “MCS tracked cognitive development through early life” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ No imaging modality is listed for MCS in reviewed public pages -> FALSE.	Response for ImagingAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Wearable / sensor Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Special data links “Special data” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ No wearable sensor stream explicitly listed -> FALSE.	Response for Wearable / sensorAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Digital phenotyping Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Special data links “Special data” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ No passive smartphone/sensor phenotyping evidence in reviewed sources -> FALSE.	Response for Digital phenotypingAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Linked health records Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Linked data summary “Researchers can access administrative health and education data linked to MCS survey data. These include Hospital Episode Statistics” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Linked health recordsAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Biosample types Recommended	saliva	Field-cited	CLS — Genetic data and biological samples https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/ Section: Stored samples “saliva (Next Steps and MCS).” Page: https://cls.ucl.ac.uk/data-access-training/genetic-data-and-biological-samples/	Response for Biosample typesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Genotyping platform Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: reviewed public pages confirm genetic/exome data but do not specify platform name for MCS in the quoted sections.	Response for Genotyping platformAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Imaging modalities Recommended	No value held	Not published	Searched — not published UNSOURCEABLE/Not applicable: no imaging modalities evidenced for MCS in reviewed sources.	Response for Imaging modalitiesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Mental health measures Recommended	No value held	Not published	Searched — not published UNSOURCEABLE as complete harmonised measure list from reviewed pages; source pages indicate measures exist but not a bounded canonical array for this field.	Response for Mental health measuresAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Data subcategories

Structured modality and subcategory rows used alongside the high-level data-type flags.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Data subcategories Recommended List key data subcategories using distinct rows for category markers, named questionnaire/interview instruments, biospecimen types, omics/genomics data products, imaging modalities, sensor streams, and linked-record types.	No value held	No source yet	No citation linked to this field yet.	Response for Data subcategoriesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Field

Current value

Evidence

Source evidence

Response

Notes / correction

Data subcategories

Recommended

List key data subcategories using distinct rows for category markers, named questionnaire/interview instruments, biospecimen types, omics/genomics data products, imaging modalities, sensor streams, and linked-record types.

No value held

No source yet

No citation linked to this field yet.

AccurateNeeds correctionNot sureDoes not apply

Consent and use permissions

Specific use permissions separate from the 3D consent-level axis.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Consent and use permissions Recommended Confirm health/biomedical research use, industry/commercial consideration, non-commercial restrictions, governance modifiers, recontact, trial approach, biosample use, linkage, sharing, international transfer, and any Section 251/CAG support.	No value held	No source yet	No citation linked to this field yet.	Response for Consent and use permissionsAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Field

Current value

Evidence

Source evidence

Response

Notes / correction

Consent and use permissions

Recommended

Confirm health/biomedical research use, industry/commercial consideration, non-commercial restrictions, governance modifiers, recontact, trial approach, biosample use, linkage, sharing, international transfer, and any Section 251/CAG support.

No value held

No source yet

No citation linked to this field yet.

AccurateNeeds correctionNot sureDoes not apply

Access pathways

One or more routes by which researchers can request or analyse data.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Access pathways Recommended Confirm all data access pathways, including route, access level, TRE/SDE or download/API environment, DAC review, collaboration requirements, data sharing agreements, output checking, timelines, and fees.	No value held	No source yet	No citation linked to this field yet.	Response for Access pathwaysAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Field

Current value

Evidence

Source evidence

Response

Notes / correction

Access pathways

Recommended

Confirm all data access pathways, including route, access level, TRE/SDE or download/API environment, DAC review, collaboration requirements, data sharing agreements, output checking, timelines, and fees.

No value held

No source yet

No citation linked to this field yet.

AccurateNeeds correctionNot sureDoes not apply

Within-cohort coverage

Aggregate counts or percentages showing how broadly data, consent, or access characteristics apply within the cohort.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Within-cohort coverage metrics Recommended Provide numerator, denominator, unit type, numerator/denominator exactness qualifiers, denominator type, basis, date/release, original source wording, and whether each metric is marginal, joint, conditional, or a release total.	No value held	No source yet	No citation linked to this field yet.	Response for Within-cohort coverage metricsAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Field

Current value

Evidence

Source evidence

Response

Notes / correction

Within-cohort coverage metrics

Recommended

Provide numerator, denominator, unit type, numerator/denominator exactness qualifiers, denominator type, basis, date/release, original source wording, and whether each metric is marginal, joint, conditional, or a release total.

No value held

No source yet

No citation linked to this field yet.

AccurateNeeds correctionNot sureDoes not apply

Linkage and access

Field	Current value	Evidence	Source evidence	Response	Notes / correction
NHS linkage Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Linked data summary “These include Hospital Episode Statistics, information from Scottish and Welsh health records” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for NHS linkageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
GP linkage Recommended	No	Not published	Searched — not published UNSOURCEABLE: linked data pages confirm health linkage generally but do not explicitly isolate GP-primary-care linkage for MCS.	Response for GP linkageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Death registry linkage Recommended	No	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Linked data summary “Researchers can access administrative health and education data linked to MCS survey data.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Reviewed public pages do not explicitly name ONS death linkage for this cohort page; conservative FALSE.	Response for Death registry linkageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Education linkage Recommended	Yes	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Linked data summary “Researchers can access administrative health and education data linked to MCS survey data.” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Education linkageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Data access mechanism Recommended	direct_application	Field-cited	CLS — Data access https://cls.ucl.ac.uk/data-access-training/data-access/ Section: Data access “Most CLS research data are publicly available through public repositories, primarily the UK Data Service.” Page: https://cls.ucl.ac.uk/data-access-training/data-access/ Access requires application/registration through repository governance -> direct_application.	Response for Data access mechanismAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
TRE platform Recommended	UK Data Service	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Explore and access the data “Most MCS data are available for free via the UK Data Service [SN 2000031].” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for TRE platformAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Data dictionary URL Recommended	https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Study homepage “Explore and access the data” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/	Response for Data dictionary URLAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Data access timeline (days) Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no numeric application-to-access timeline published.	Response for Data access timeline (days)AccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Data access cost Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: reviewed sources do not provide a cohort-specific access cost schedule.	Response for Data access costAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Participant profile and dates

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Age distribution Recommended	No value held	Not published	Searched — not published UNSOURCEABLE from reviewed public sources: no exact JSON-compatible age-band percentages published on accessed pages.	Response for Age distributionAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Sex distribution Recommended	No value held	Not published	Searched — not published UNSOURCEABLE from reviewed public sources: no exact current sex-distribution percentages published on accessed pages.	Response for Sex distributionAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Ethnicity distribution Recommended	No value held	Not published	Searched — not published UNSOURCEABLE from reviewed public sources: no exact current ethnicity-distribution percentages published on accessed pages.	Response for Ethnicity distributionAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Smoking status distribution Recommended	No value held	No source yet	No citation linked to this field yet.	Response for Smoking status distributionAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Median age Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no precise median age value published on reviewed pages.	Response for Median ageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Percent female Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no exact female percentage in reviewed public pages; value set NULL.	Response for Percent femaleAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Percent non-white Recommended	No value held	Not published	Searched — not published UNSOURCEABLE: no exact non-white percentage in reviewed public pages; value set NULL.	Response for Percent non-whiteAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Geographic coverage Recommended	national	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro “born across England, Scotland, Wales and Northern Ireland” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ All four UK nations covered -> national.	Response for Geographic coverageAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Follow-up duration Recommended	24+ years (2000-present)	Field-cited	CLS — Millennium Cohort Study https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Section: Intro + sweeps “born ... in 2000-02 ... Data are available from eight main sweeps” Page: https://cls.ucl.ac.uk/cls-studies/millennium-cohort-study/ Cohort spans from birth (2000-02) to current age 23 sweep, i.e., 24+ years in 2026.	Response for Follow-up durationAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Last data collection date Recommended	No value held	Not published	Searched — not published UNSOURCEABLE as exact date from reviewed pages; only wave-level statements were available.	Response for Last data collection dateAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Recruitment start date Recommended	1 Sept 2000	Field-cited	PubMed abstract — MCS cohort profile https://pubmed.ncbi.nlm.nih.gov/24550246/ Section: Abstract “children born at the turn of the new century” Page: https://pubmed.ncbi.nlm.nih.gov/24550246/ Start month sourced from cohort design window (2000-09 to 2002-01) used in seed data.	Response for Recruitment start dateAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Recruitment end date Recommended	31 Jan 2002	Field-cited	PubMed abstract — MCS cohort profile https://pubmed.ncbi.nlm.nih.gov/24550246/ Section: Abstract “children born at the turn of the new century” Page: https://pubmed.ncbi.nlm.nih.gov/24550246/ End month sourced from cohort design window (2000-09 to 2002-01) used in seed data.	Response for Recruitment end dateAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Diagnosis areas

Mental health diagnosis areas represented in this cohort.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Diagnosis area: Major depressive disorder Recommended Confirm this diagnosis area applies and estimated N if shown.	Major depressive disorder · Mood Disorders	Field-cited	CLS — One in four girls is depressed at age 14 https://cls.ucl.ac.uk/one-in-four-girls-is-depressed-at-age-14-new-study-reveals/ Section: News article “24 per cent of girls and 9 per cent of boys are depressed at age 14.” Page: https://cls.ucl.ac.uk/one-in-four-girls-is-depressed-at-age-14-new-study-reveals/ MDD diagnosis area is evidenced, but a cohort-wide diagnosis count is not directly derivable from sex-stratified age-14 symptom rates -> estimated_n NULL.	Response for Diagnosis area: Major depressive disorderAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Diagnosis area: Generalised anxiety disorder Recommended Confirm this diagnosis area applies and estimated N if shown.	Generalised anxiety disorder · Anxiety Disorders	Field-cited	CLS — One in four girls is depressed at age 14 https://cls.ucl.ac.uk/one-in-four-girls-is-depressed-at-age-14-new-study-reveals/ Section: News article “18 per cent having symptoms of depression and anxiety” Page: https://cls.ucl.ac.uk/one-in-four-girls-is-depressed-at-age-14-new-study-reveals/ GAD diagnosis area retained from explicit anxiety symptom evidence; no diagnosis-specific count published -> estimated_n NULL.	Response for Diagnosis area: Generalised anxiety disorderAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Diagnosis area: ADHD Recommended Confirm this diagnosis area applies and estimated N if shown.	ADHD · Neurodevelopmental · est. n=264	Field-cited	Russell et al. — ASD and ADHD prevalence in MCS https://doi.org/10.1007/s10803-013-1849-0 Section: Abstract “1.4 % reportedly had ADHD” Page: https://pubmed.ncbi.nlm.nih.gov/23719853/ Derived estimated_n = round(18827 * 0.014) = 264. Russell et al. — ASD and ADHD prevalence in MCS https://doi.org/10.1007/s10803-013-1849-0 Section: Abstract “1.4 % reportedly had ADHD” Page: https://pubmed.ncbi.nlm.nih.gov/23719853/	Response for Diagnosis area: ADHDAccurateNeeds correctionNot sureDoes not apply No response selected	No notes
Diagnosis area: Autism spectrum conditions Recommended Confirm this diagnosis area applies and estimated N if shown.	Autism spectrum conditions · Neurodevelopmental · est. n=320	Field-cited	Russell et al. — ASD and ADHD prevalence in MCS https://doi.org/10.1007/s10803-013-1849-0 Section: Abstract “1.7 % of children were reported as having ASD” Page: https://pubmed.ncbi.nlm.nih.gov/23719853/ Derived estimated_n = round(18827 * 0.017) = 320. Russell et al. — ASD and ADHD prevalence in MCS https://doi.org/10.1007/s10803-013-1849-0 Section: Abstract “1.7 % of children were reported as having ASD” Page: https://pubmed.ncbi.nlm.nih.gov/23719853/	Response for Diagnosis area: Autism spectrum conditionsAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Linked sites

Sites contributing participants or data to this cohort.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Linked sites Optional	No value held	No source yet	No citation linked to this field yet.	Response for Linked sitesAccurateNeeds correctionNot sureDoes not apply No response selected	No notes

Verification metadata

Internal catalogue status — for reference only.

Field	Current value	Evidence	Source evidence	Response	Notes / correction
Verification status Recommended	unverified	Internal	Internal catalogue field	—	—
Last verified Recommended	No value held	Internal	Internal catalogue field	—	—
Data source Recommended	No value held	Internal	Internal catalogue field	—	—