1 Department of Gastroenterology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
2 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
3 Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
4 Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institute, Stockholm, Sweden.
5 Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, School of Medical Sciences, Örebro University, Örebro, Sweden.
6 Unit of Integrative Epidemiology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
7 Department of Epidemiology and Public Health, University College London, London, UK.
8 Department of Paediatrics, Örebro University Hospital, Örebro, Sweden.
9 Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA.
10 Department of Clinical Science and Education, Sachs' Children and Youth Hospital, Stockholm South General Hospital, Karolinska Institute, Stockholm, Sweden.