1. Ear, Nose and Throat Clinic; Blekinge Hospital; Karlskrona Sweden
2. Pediatric and Neonatology Unit; Ospedale San Paolo; Savona Italy
3. Cochrane Austria, Department for Evidence-based Medicine and Evaluation; Danube University Krems; Krems Austria
4. Paediatrics, Department of Clinical Sciences Lund; Lund University, Skåne University Hospital; Lund Sweden
5. Cochrane Sweden, Department of Research and Education; Lund University, Skåne University Hospital; Lund Sweden
6. Department of Clinical Sciences Lund; Lund University, Skåne University Hospital; Lund Sweden