1. Division of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
2. Department of Internal Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden
3. Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden
4. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
5. School of Medicine, Tohoku University, Sendai, Japan