title: Can the Ottawa knee rule be applied to children? A systematic review and meta-analysis of observational studies.
abstract: BACKGROUND
  The Ottawa knee rule (OKR), a clinical decision aid is used to reduce unnecessary radiography. It is not clear whether this rule can be applied to children.
  
  
  OBJECTIVE
  To establish whether the OKR had adequate sensitivity and acceptable specificity in children to advocate widespread use.
  
  
  METHODS
  A systematic review and meta-analysis was conducted of observational studies that examined the diagnostic characteristics of the OKR in children.
  
  
  METHODS
  Relevant English language articles were identified from Medline (1950 to date), EMBASE (1974 to date), CINAHL (1982 to date), the Cochrane Library, Google Scholar and a hand search of bibliographies.
  
  
  METHODS
  Observational studies that included children and have used the OKR for ruling out fractures in children either radiologically or in combination with follow-up.
  
  
  RESULTS
  Four relevant studies were identified. Three studies were suitable for inclusion in the meta-analysis, representing 1130 children. The pooled negative likelihood ratio was 0.07 (95% CI 0.02 to 0.29), the pooled positive likelihood ratio was 1.94 (95% CI 1.60 to 2.36), the pooled sensitivity was 99% (CI 94.4 to 99.8) and the pooled specificity was 46% (CI 43.0 to 49.1). The reduction in radiography was between 30% and 40%.
  
  
  CONCLUSIONS
  The OKR has high sensitivity and adequate specificity for children over the age of 5 years. There are not enough good data to advocate application of the OKR in children less than 5 years.
authors.affiliation: Peterborough District Hospital, Peterborough, UK.
authors.forename: D
authors.initials: D
authors.lastname: Vijayasankar
authors.forename: A A
authors.initials: AA
authors.lastname: Boyle
authors.forename: P
authors.initials: P
authors.lastname: Atkinson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003661:Decision Support Techniques; D050723:Fractures, Bone / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D007718:Knee Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018579:Patient Selection; D011859:Radiography; D012680:Sensitivity and Specificity; D019564:Unnecessary Procedures / Q000706:statistics & numerical data