1 Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
2 Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; Department of Primary Care and Population Health, University College London, London, UK.
3 Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
4 Boston Collaborative Drug Surveillance Program, Boston University School of Public Health, Boston, MA, USA.
5 Department of Pediatrics and School of Epidemiology, Public Health and Preventive Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.
6 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, University Hospital of Örebro, Sweden.