In a breakthrough for primary care research in Wales, ADR Wales researchers have developed a Research-Ready Data Asset (RRDA) for the Welsh Longitudinal General Practice (WLGP) data, enabling more efficient and comprehensive analysis of general practice activity spanning over three decades.
This curated data resource, developed within the SAIL Databank, the national trusted research environment (TRE) for Wales, aimed to standardise the curation of primary care records, enhance reproducibility, and provide deeper insights into healthcare trends, particularly in the wake of the COVID-19 pandemic.
Details of the method and associated RRDA, along with the team’s research on the impact of COVID-19 on the utilisation of primary care services, have been published in PLOS ONE.
A comprehensive, structured data asset for research
The creation of the RRDA involved data cleaning, curation, and the transformation of records into a structured, normalised format that supports large-scale queries. The RRDA covers more than 4.6 billion records from 5.1 million people across Wales, currently spanning from 1990 to 2024. This extensive RRDA offers a unique opportunity for longitudinal analysis of primary care activity before, during and after the COVID-19 pandemic.
The WLGP RRDA also includes a comprehensive lookup of official and local primary care clinical codes (Read V2, SNOMED, EMIS, and Vision). In addition, the team implemented a four-layer classification system to identify healthcare provider type, patient access mode, interaction type, and details. This framework captures the complexity of activity recorded in primary care and enables deeper analysis of patient–practice interactions at scale.
Initial findings showed a marked increase in primary care activity over the years, with consultation rates rising by 1.9 times between 2000 and 2024. Particularly notable was the rise in post-pandemic consultations, which have remained 8% above pre-pandemic levels. Similarly, prescription-only activities doubled, and vaccination rates spiked during the pandemic, remaining 1.8 times higher than those seen prior to COVID-19.
The RRDA’s ability to enable these detailed insights and trends underscores its importance in shaping policy and guiding healthcare decision-making in Wales.
Improved data coverage, quality, and research reproducibility
One of the key contributions of the RRDA work is the improved understanding of how the quality and completeness of primary care data have evolved over time. Through detailed curation, it was shown that the recording of primary care events has become far more consistent in recent years, with a greater proportion of records and patients retained after curation. This reflects improvements in coding practices, recording systems, and data submission processes across Wales. The RRDA therefore, not only enables high-quality research but also provides new visibility into the evolution of data quality, offering a scalable, transparent foundation for studies of clinical practice, healthcare access, and patient outcomes.
With its ability to capture the evolving dynamics of primary care in Wales, the RRDA will be a key resource for researchers, clinicians, and policymakers alike in understanding the impact of global events, like the COVID-19 pandemic, on healthcare systems and patient care.
Dr Hoda Abbasizanjani, joint lead author of the study and ADR Wales Senior Research Officer, said: “Routine data carries enormous potential, but it also requires careful handling to ensure analyses are robust and interpretable. Developing the WLGP RRDA has been a major step toward improving the quality, consistency and usability of primary care data in Wales. By creating a resource that supports reproducible, high-quality research, we’re enabling a clearer understanding of how primary care is changing—and ultimately helping to inform improvements in services for people across Wales.”
Dr Stuart Bedston, joint lead author of the study and ADR Wales Senior Research Officer, said: “Our new research ready data asset (RRDA) shows that Welsh primary care didn’t just recover after COVID-19, but that consultations are now higher than ever.”
Professor Ashley Akbari, Professor of Population Data Science Research at Swansea University, said: “The creation of these types of reproducible, maintainable research ready data assets (RRDAs) is a key focus of our team, ensuring that the learning we achieve through each project output has the potential to be (re)used and hopefully inform and enable more efficient future team science research opportunities, and act as a foundation for prospective further developments and activities. The linked primary care data in SAIL is a fantastic data resource for a wide range of current and potential future projects, and we hope this RRDA and its additional features will add value and impact in the years to come.”
For more information about the WLGP and other data you can access, visit the SAIL Databank.