The UK Government established the National Core Studies (NCS) initiative in Summer 2020 to tackle the unique combination of health risks posed by the COVID-19 pandemic. Experts and key research funders were rallied to identify several areas where the UK needed to increase scale and infrastructure to respond to the immediate challenges. 

The Data and Connectivity NCS was established as a result. Jointly led by Health Data Research UK (HDR UK) and the Office for National Statistics (ONS), its function is to connect UK health data and provide the data solutions that are crucial for the NCS strategic programmes to accelerate COVID-19 research.  

The challenge

Data and Connectivity needed to bring together medical, biological and social science data on an unprecedented scale, from across the four UK nations.  

In Wales, the Secure Anonymised Information Linkage (SAIL) Databank is one of the best characterised population databanks found anywhere in the world, containing 100% data coverage for secondary care and 80% coverage of primary care for the population of Wales. The data consists of anonymised individual-level, population-scale records that span health, administrative, social care, justice, housing and education data. 

This data coverage, along with SAIL’s well-established infrastructure, robust governance mechanisms, high-performance computing capabilities and emphasis on public involvement meant they were well-placed to take on a central role to support the UK’s COVID-19 response through Data and Connectivity. Members of the SAIL team came together with key stakeholders across HDR UK, Administrative Data Research UK (ADR UK), Welsh Government, Public Health Wales and the public in what became known as the ‘One Wales‘ response to develop an agile approach to data analysis which would help policymakers tackle COVID-19 in Wales and across the UK. 

Ronan Lyons

Clinical Professor of Public Health and Co-Director of SAIL Databank, Ronan Lyons OBE, commented:

“The emergence of COVID-19 presented us with a public health challenge of unparalleled scale. When the call came to support the Data and Connectivity arm of NCS we knew that SAIL Databank could, and should, play a central role. Owing to the hard work of the SAIL Databank team over the last 15 years, we were able to leverage our networks, processes and technology to strengthen NCS efforts.” 


“We quickly established new COVID-19 data flows and raised the cadence of our existing routinely-collected data by virtue of a dynamic partnership with Digital Health and Care Wales who facilitate data transfer and anonymisation. I’m incredibly proud of our team’s achievements and grateful to our partners, whose extraordinary efforts have had a huge impact on the national response to keep people safe during this pandemic.”. 

The impact

The SAIL Databank, HDR UK and the other collaborators which form the One Wales response have successfully brought data controllers and researchers together to answer a broad range of research questions to tackle the COVID-19 pandemic and beyond. From analysis of early vaccination data to show there was no significant risk of rare clotting events for the elderly, to highlighting vaccination gaps between ethnic minorities and the general population. 

Andrew Morris

Professor Andrew Morris, Director of Health Data Research UK, commented:

“The collaborative approach demonstrated by the One Wales initiative has been crucial in enabling vital insights at pace into COVID-19. These have directly informed Welsh Government policy, including providing evidence for targeted interventions to support the needs of those shieldinghealthcare workers, and people living in deprived areasmapping COVID-19 ‘hotspots’ to inform Government’s lockdown strategy; and informing the government’s subsequent approach to re-opening schools.” 


“HDR UK, in partnership with the ONS, are delighted to have supported this work through the Data and Connectivity NCS, which has supported crucial linked data sets to be made available for this research.” 

The new data sets, along with the increased cadence and availability of existing SAIL data sources, that have enabled these insights can continue to answer pressing COVID-19 research questions. They include: 


The One Wales initiative wishes to acknowledge the collaborative partnership which was led by the Swansea University Health Data Research UK team under the direction of the Welsh Government Technical Advisory Cell (TAC) and includes the following groups and organisations: the Secure Anonymised Information Linkage (SAIL) Databank, Administrative Data Research (ADR) Wales, Digital Health and Care Wales (DHCW formerly NHS Wales Informatics Service (NWIS)), Public Health Wales, NHS Shared Services and the Welsh Ambulance Service Trust (WAST). All research conducted has been completed under the permission and approval of the SAIL independent Information Governance Review Panel (IGRP) project number 0911. 

The work completed by the One Wales collaboration uses data provided by patients and collected by the NHS as part of their care and support. We would also like to acknowledge all data providers who make anonymised data available for research.