EVALUATION OF THE OTTAWA CLINICAL DECISION RULES FOR THE USE OF RADIOGRAPHY IN ACUTE ANKLE AND MIDFOOT INJURIES IN THE EMERGENCY DEPARTMENT- AN INDEPENDENT SITE ASSESSMENT

Study objective: Decision rules for the use of radiography in acute an kle and midfoot injuries have been developed. Radiographs are indicate d if there is tenderness at the posterior edge or tip of either malleo lus or at the navicular or base of the fifth metatarsal or there is in ability to both weight bear immediately after the injury and ambulate four steps in the emergency department. This study assessed the effica cy of these rules with health care providers who had not been involved in their development. Design: Prospective patient survey by emergency department attending physicians and triage nurses. Setting: EDs of a university hospital and a community hospital with a combined annual vo lume of 100,000. Participants: One hundred ten patients older than 16 years who presented with acute blunt ankle and midfoot trauma during t he 3 months of summer 1993. Results: Fourteen fractures were diagnosed . When used by ED attending physicians, the decision rules had a sensi tivity of 1.0 and specificity of 0.19 in detecting all midfoot and ank le fractures. When used by triage nurses, the sensitivity was 0.9 and specificity was 0.1. The negative predictive values of the decision ru les were 1.0 for ED attending physicians and 0.88 for triage nurses. E D attending physicians and triage nurses agreed in 90% of cases regard ing the overall decision to obtain radiographs. However, there was onl y a 47% agreement on all components of the clinical decision rules, wi th kappa values ranging from 0.60 to 0.76. The accuracies of the predi ctive rules were similar as applied by the ED attending physicians and the triage nurses (chi2, P = .23). Application of the Ottawa predicti ve rules by ED attending physicians would have resulted in a 19% reduc tion in use of midfoot and ankle radiographs.