1. Finnish Institute of Occupational Health, Neulaniementie 4, 70210 Kuopio, Finland
2. Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland
3. Finnish Institute of Occupational Health, Topeliuksenkatu 41, 00250 Helsinki, Finland
4. Department of Public Health, University of Helsinki, Yliopistonkatu 4, 00014 Helsinki, Finland