SEPLINE was founded by Maja Halgren Olsen, postdoc at the Danish Cancer Institute, and Cathrine F. Hjorth, postdoc at Department of Clinical Epidemiology, Aarhus University. The idea arose from their shared experience of the challenges posed by inconsistent approaches to measuring socioeconomic differences across research institutions.

They observed that large variations in how socioeconomic position is defined and analyzed can lead to misinterpretations and hinder efforts to address health differences. Additionally, researchers often spend a significant amount of time navigating complex data sources. SEPLINE seeks to make this work more accessible and coherent. The national and interdisciplinary network was established in 2023 with support from the Danish Comprehensive Cancer Center.

Through two workshops in 2024 and an ongoing collaboration with researchers across Danish universities and public institutions, SEPLINE has developed a consensus guideline that offers practical recommendations on how to measure socioeconomic position and analyze social differences in health outcomes. It also highlights common pitfalls and limitations in commonly used data sources.

By fostering shared practices and better methodological understanding, SEPLINE hopes to strengthen the foundation for valid and comparable research across institutions. The guideline is intended to be a helpful resource for researchers designing studies on prevention, treatment, and rehabilitation – across all areas of health.

The initiative will also contribute to education and capacity building, including a new PhD course at Aarhus University scheduled in the fall of 2025.