UK Longitudinal Linkage Collaboration (UK LLC): The National Trusted Research Environment for Longitudinal Research
Authors: Boyd Andy , Evans Katharine , Turner Emma L. , Flaig Robin , Oakley Jacqui , Campbell Kirsteen C. , Thomas Richard , McLachlan Stela , Crane Matthew , Whitehorn Rebecca , Calkin Rachel , Hill Abigail , Berman Samantha , Ford David , Tobin Martin , Porteous David , Gomes Danielle F. , Garcia Maria-Paz , Wong Andrew , Sanchez Aida , Orton Chris , Thompson Simon , Gulliver John , Adams Kathryn , Badrick Ellena , Batini Chiara , Benzeval Michaela , Boatman Susie , Breen Gerome , Bristow Shannon , Britten Abigail , Bryant Luke , Butterworth Adam , Campbell Archie , Chave Sarah , Danesh John , Das-Munshi Jayati , Dennison Karen , Angelantonio Emanuele Di , Eley Thalia C. , Fisher Helen , Fitzsimons Emla , Goodman Alissa , Gregg Michael , Guyatt Anna L , Hansell Anna , Harmston Rebecca , Heard Andy , Henderson Morag , Hill Rosie , Huang Szu-Chia , John Catherine , Kee Frank , Kingston Nathalie , Kneeshaw Jack , Kumar Rashmi , Lachance Genevieve , Lockhart Celestine , Lockhart-Jones Hazel , Markham Sarah , Mason Dan , McGuinness Bernadette , McKenzie Maisie , McMahon Amy , Malouf Chelsea Mika , Mumme Mark , Neville Charlotte , Northstone Kate , Oldfield Zoe , O’Neill Dara , Pareek Manish , Pickavance John , Rahman Yasmin , Reilly Holly , Scott Angela , Smith Deb , Steptoe Andrew , Steves Claire , Sudlow Cathie , Sze Gerald , Timpson Nicholas L. , Tungamirai Tapiwa , Venn Laura , Walker Matthew , Walker Neil , Wareham Nicolas , Watmuff Aidan , Webb Tony , Williams Karen , Wright John , Yarand Darioush , Ploubidis George B , Macleod John , Sterne Jonathan AC. , Chaturvedi Nishi 
Published: February 2025

IntroductionThe UK Longitudinal Linkage Collaboration (UK LLC) is the national Trusted Research Environment (TRE) for the UK's longitudinal research community, supporting the UK's unparalleled collection of Longitudinal Population Studies (LPS). Initially set up as a COVID-19 research resource, UK LLC is now a generic database for any research for the public good.
ObjectivesUK LLC supports longitudinal research by providing record linkage and TRE services.
MethodsThe UK LLC partnership provides a secure analytics environment, a trusted third-party linkage processor and a comprehensive governance framework to minimise risks to participant confidentiality. UK LLC is ISO 27001 certified and accredited by the UK Statistics Authority as a processor under the Digital Economy Act. The active involvement by members of UK LLC's public involvement programme ensures UK LLC is acceptable to LPS participants and the wider public. All UK LPS are eligible for inclusion. Researchers can apply to access the TRE via an approach that fulfils the needs of the LPS, the linked data owners and includes a review by public contributors.
ResultsTwenty-two LPS have so far joined UK LLC. Where permissions allow, participants are linked to their National Health Service (NHS) England, NHS Wales and place-based records, with work ongoing to link to NHS Scotland and non-health administrative records, including Department for Work and Pensions and His Majesty's (HM) Revenue and Customs. UK LLC Explore allows potential researchers to discover the breadth of data available in the TRE. All applications are listed on UK LLC's publicly accessible Data Access Register.
ConclusionsUK LLC enables researchers to interrogate pooled LPS participant data that are systematically linked to diverse records. UK LLC remains open to additional LPS joining the partnership and will increase the breadth of data to support the longitudinal research community and attract increasing numbers of researchers across multiple disciplines, government departments and industry.