1 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm and Department of Pediatrics, Örebro University Hospital, Örebro, Sweden and Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK and Celiac Disease Center, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York.
2 Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
3 Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Sweden and School of Public Health, University of California, Berkeley, California.