Objective: To assess the impact on clinical practice of implementing the Ottawa ankle rules.
Design: Nonrandomized, controlled trial with before-after and concurrent controls.
Setting: Emergency departments of a university (intervention) hospital and a community (control) hospital.
Patients: All 2342 adults seen with acute ankle injuries during 5-month periods before and after the intervention.
Intervention: The implementation of the Ottawa ankle rules by emergency department physicians.
Main outcome measure: Proportions of patients referred for standard ankle and foot radiographic series.
Results: There was a relative reduction in ankle radiography by 28% at the intervention hospital but an increase by 2% at the control hospital (P < .001). Foot radiography was reduced by 14% at the intervention hospital but increased by 13% at the control hospital (P < .05). Compared with nonfracture patients who had radiography during the after period at the intervention hospital, those discharged without radiography spent less time in the emergency department (80 minutes vs 116 minutes; P < .0001), had lower estimated total medical costs for physician visits and radiography ($62 vs $173; P < .001), but did not differ in the proportion satisfied with emergency physician care (95% vs 96%) or undergoing subsequent radiography (5% vs 5%). The rules were found to have sensitivities of 1.0 (95% confidence interval [CI], 0.95 to 1.0) for detecting 74 malleolar fractures and 1.0 (95% CI, 0.82 to 1.0) for detecting 19 midfoot fractures. In the following 12 months at the intervention hospital, use of radiography did not increase.
Conclusions: Implementation of the Ottawa ankle rules led to a decrease in use of ankle radiography, waiting times, and costs without patient dissatisfaction or missed fractures. Future studies should address the generalizability of these decision rules in a variety of hospital settings.