LONELY-EU WP3_1A: Database of Loneliness Datasets in Europe

This project documents work carried out within LONELY-EU, a Horizon Europe project aimed at strengthening the evidence base on loneliness across Europe. It hosts the technical report, documentation, and interactive resources developed under WP3_1A, which focuses on mapping and organizing existing data on loneliness in the European Union and the United Kingdom. Using a preregistered search protocol, we systematically identified and screened hundreds of datasets from major data repositories and the academic literature. For each dataset, we documented key metadata and detailed information on how loneliness is measured, including item wording, response scales, and the use of validated instruments. These data were integrated into a single, searchable database designed to facilitate data discovery, support systematic assessment of measurement heterogeneity and cross-dataset comparability, and identify substantive and geographic gaps in the current evidence base. To enhance accessibility and usability, the database is accompanied by an interactive web interface that allows researchers, policymakers, and third-sector stakeholders to explore and filter datasets according to their analytical needs. Together, these resources provide a transparent and reusable infrastructure for research and policy work on loneliness in Europe, and serve as a foundation for subsequent analyses within LONELY-EU.