1. Paediatric Department; Herlev Hospital; Herlev Denmark
2. H.C. Andersen Children's Hospital; Odense University Hospital; Odense C Denmark
3. Paediatric Department; Kolding Hospital; Kolding Denmark
4. Paediatric Department; Aalborg University Hospital; Aalborg Denmark
5. Section of Biostatistics; Department of Public Health; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
6. Paediatric Department; Regionshospitalet Viborg; Viborg Denmark
7. Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark