INVEST enhances the use of unique register data by strengthening collaboration

The use of the INVEST Full Population Data – a register-based dataset developed by INVEST Research Flagship Centre – is being advanced through closer collaboration. By uniquely combining data from Finnish Institute for Health and Welfare (THL), Statistics Finland and Kela, the dataset provides researchers with an exceptional opportunity to conduct research on a global scale.

Researchers from the University of Turku and THL gathered for a joint workshop to explore ways to further strengthen collaboration between the organisations.

“Our goal is to deepen collaboration and enable more efficient use of the data,” said Outi Sirniö, one of the principal investigators responsible for the dataset at INVEST Research Flagship Centre and Research Manager at THL.

“We conduct extensive register-based research and are at the forefront in Finland and the Nordic countries – and even globally. We have data that are not available anywhere else,” added Academy Professor Jani Erola, Director of the INVEST Research Flagship Centre.

A key strength of the INVEST Full Population Data lies in its ability to combine information from multiple sources, enabling more comprehensive and in-depth research.

“Building the register has required substantial investment, particularly in data protection and data harmonisation. The result is a unique research environment where even sensitive data can be used securely,” Sirniö noted.

Research Manager Matti Lindberg told, that currently, around one hundred researchers at the INVEST Research Flagship Centreuse the Full Population Data.

The workshop also showcased new datasets and research initiatives. Collegium researcher Aleksi Karhula presented INVEST – Longitudinal study on wellbeing (https://sites.utu.fi/seurantatutkimus/en/front-page/), the first datasets of which are already available to INVEST researchers and also to everyone via the Finnish Social Science Data Archive. Launched in 2024, the study collects panel data from Finns aged 18 to 80 over several years and there is a possibility to link the survey to register data.

“Within a few years, the data will allow for follow-up analyses and the study of change over time,” Karhula explained.

The dataset offers a wide range of research opportunities and has also been used by master’s students within INVEST.

Senior researcher Henri Salokangas presented a new dataset compiled at THL from administrative court records (LASTU), covering all court decisions on out-of-home placements in Finland from 2000 to 2025. The court documents contain testimonies from social workers and other experts that shed light on the difficult circumstances behind placement decisions. Linked to the INVEST register environment, the dataset enables enables researchers to examine the connections between these adverse background factors and the long-term life trajectories of children in out-of-home care, using on information on  education, health, and criminal justice outcomes..

The day concluded with workshops in which participants developed new joint research ideas in small groups. The aim is to further strengthen collaboration, particularly between the University of Turku and THL, and to make even better use of the unique data resources available.