1 PEDEGO Research Unit, University of Oulu, Oulu, Finland; Department of Dermatology and Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland.
2 Infrastructure for Population Studies, Faculty of Medicine, University of Oulu, Finland.
3 Center for Life Course Epidemiology and Systems Medicine, University of Oulu, Oulu, Finland.
4 PEDEGO Research Unit, University of Oulu, Oulu, Finland; Department of Dermatology and Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland. Electronic address: kaisa.tasanen@oulu.fi.