1. Department of Welfare, National Institute for Health and Welfare (THL), Oulu, Finland
2. PEDEGO Research Unit, University of Oulu, Oulu, Finland
3. Research Department, Social Insurance Institution (KELA), Helsinki, Finland
4. Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
5. Information Services Department, National Institute for Health and Welfare (THL), Helsinki, Finland
6. Research Department, Finnish Centre for Pensions (ETK), Helsinki, Finland