1. Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York, New York
2. Mailman School of Public Health, Department of Epidemiology, Columbia University, New York, New York
3. Department Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
4. Department of Pediatrics, Örebro University Hospital, Örebro University, Örebro, Sweden