Affiliation: | 1. Department of PharmacoEpidemiology & PharmacoEconomics, University Centre of Pharmacy, University of Groningen, , Groningen, The Netherlands;2. Department of Pediatrics, Medical Centre Leeuwarden, , Leeuwarden, The Netherlands;3. Department of Epidemiology, Boston University School of Public Health, , Boston, MA, USA;4. Boston Collaborative Drug Surveillance Program, , Boston, MA, USA;5. Department of Epidemiology, University Medical Centre Groningen, , Groningen, The Netherlands |