title: The incidence and aetiology of acute kidney injury in children in Norway between 1999 and 2008.
abstract: OBJECTIVE
  Primary acute kidney injury (AKI) is a direct cause of hospitalisation in children, but can also result from other conditions. There is limited information on the epidemiology of this condition. Our aim was to describe the national incidence rate and aetiology of acute kidney injury in children under the age of 16 in Norway from 1999 to 2008.
  
  
  METHODS
  We carried out a retrospective study of medical records provided by all 18 of the paediatric hospital departments that specialise in treating paediatric patients with AKI.
  
  
  RESULTS
  We identified 315 cases of AKI (53% male), with an estimated average annual incidence rate of 3.3 cases per 100 000 children and a median annual occurrence of 33 cases. Most cases (43%) were in children under five. We identified 53 aetiologies and classified these into 30 aetiological groups: 24% of the cases were prerenal (n = 75), 74% were intrinsic/renal (n = 234) and 2% were postrenal (n = 5). Nephritic syndromes was the major cause (44%) of AKI, followed by haemolytic-uraemic syndrome (HUS) (15%).
  
  
  CONCLUSIONS
  Nephritic syndromes and HUS are the most common aetiologies of AKI in Norway. Although our results could indicate a low incidence of paediatric AKI in Norway, the lack of other national studies makes comparisons difficult.
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health (Nasjonalt Folkehelseinstitutt), Oslo, Norway.|Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Gaute Reier
authors.initials: GR
authors.lastname: Jenssen
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health (Nasjonalt Folkehelseinstitutt), Oslo, Norway.|Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Eirik
authors.initials: E
authors.lastname: Hovland
authors.affiliation: Department of Pediatrics, Oslo University Hospital, Oslo, Norway.
authors.forename: Hans-Jacob
authors.initials: HJ
authors.lastname: Bangstad
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health (Nasjonalt Folkehelseinstitutt), Oslo, Norway.
authors.forename: Karin
authors.initials: K
authors.lastname: Nygård
authors.affiliation: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health (Nasjonalt Folkehelseinstitutt), Oslo, Norway.
authors.forename: Line
authors.initials: L
authors.lastname: Vold
authors.affiliation: Department of Pediatrics, Oslo University Hospital, Oslo, Norway.
authors.forename: Anna
authors.initials: A
authors.lastname: Bjerre
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000209:etiology*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009664:Norway / Q000453:epidemiology; D012189:Retrospective Studies; D013997:Time Factors
keywords: Acute kidney injury; Aetiology; Epidemiology; Haemolytic-uraemic syndrome; Nephritic syndrome