1 Center for Clinical Research Dalarna, Uppsala University, Falun, Region Dalarna, Sweden; School of Health and Welfare, Dalarna University, Falun, Region Dalarna, Sweden.
2 Department of Political Sciences, University of Pisa, Pisa, Administrative Region of Tuscany, Italy.
3 Department of Statistics, Uppsala University, Uppsala, Region Uppsala, Sweden; Yau Mathematical Science Center, Tsinghua University, Beijing, China.