title: Failed validation of a clinical decision rule for the use of radiography in acute ankle injury.
abstract: OBJECTIVE
  To validate the Ottawa clinical decision rule for the use of radiography in acute ankle injuries.
  
  
  METHODS
  A prospective, multicentre trial of 350 adult patients presenting with acute ankle injuries consisting of correlation of the features of the Ottawa clinical decision rule with the results of x-rays.
  
  
  RESULTS
  There were 75 fractures in 350 patients, five of which would have been missed by the clinical decision rule. The sensitivity of the rule was 93% with a specificity of 11%. The positive predictive value was 22%, the false negative rate 14%. Fractures that would have been missed by the clinical decision rule included one unstable fracture of the ankle, one fracture of the talus, one calcaneal fracture and one fracture each of the cuboid and navicular.
  
  
  CONCLUSIONS
  The Ottawa clinical decision rule for the use of radiography in acute ankle injuries is unacceptable for application in emergency departments in New Zealand due to a high false negative rate.
authors.affiliation: Emergency Department Hutt Hospital, Lower Hutt, New Zealand.
authors.forename: A M
authors.initials: AM
authors.lastname: Kelly
authors.forename: D
authors.initials: D
authors.lastname: Richards
authors.forename: L
authors.initials: L
authors.lastname: Kerr
authors.forename: J
authors.initials: J
authors.lastname: Grant
authors.forename: P
authors.initials: P
authors.lastname: O'Donovan
authors.forename: K
authors.initials: K
authors.lastname: Basire
authors.forename: R
authors.initials: R
authors.lastname: Graham
mesh_terms: D000208:Acute Disease; D016512:Ankle Injuries / Q000000981:diagnostic imaging*; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital; D005188:False Negative Reactions; D006801:Humans; D009864:Ontario; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity