Affiliation: | 1. Department of Paediatrics, Angered Hospital, Gothenburg, Sweden;2. North Älvsborg Hospital, Trollhättan, Sweden;3. Department of Paediatrics, South Älvsborg Hospital, Borås, Sweden;4. Department of Paediatrics, Sahlgrenska University Hospital, Gothenburg, Sweden Correspondence Birger Trollfors, Department of Paediatrics, Sahlgrenska University Hospital, Gothenburg 41685, Sweden. Tel: +46313434000 | Fax: +4631843010 | Email: birger.trollfors@vgregion.se |