IMPLEMENTATION OF THE OTTAWA KNEE RULE FOR THE USE OF RADIOGRAPHY IN ACUTE KNEE INJURIES

Context.-The Ottawa Knee Rule is a previously validated clinical decis ion rule that was developed to allow physicians to be more selective a nd efficient in their use of plain radiography for patients with acute knee injuries. Objective.-To assess the impact on clinical practice o f implementing the Ottawa Knee Rule. Design.-Controlled clinical trial with before-after and concurrent controls. Setting.-Emergency departm ents of 2 teaching and 2 community hospitals. Patients.-All 3907 conse cutive eligible adults seen with acute knee injuries during two 12-mon th periods before and after the intervention. Intervention.-During the after period in the 2 intervention hospitals, the Ottawa Knee Rule wa s taught to ail house staff and attending physicians who were encourag ed to order knee radiography according to the rule. Main Outcome Measu res.-Referral for knee radiography, accuracy and reliability of the ru le, mean time in emergency department, and mean charges. Results.-Ther e was a relative reduction of 26.4% in the proportion of patients refe rred for knee radiography in the intervention group (77.6% vs 57.1%; P <.001), but a relative reduction of only 1.3% in the control group (76 .9% vs 75.9%; P=.60). These changes over ti me were significant when t he intervention and control groups were compared (P<.001). The rule wa s found to have a sensitivity of 1.0 (95% confidence interval [CI], 0. 94-1.0) for detecting 58 knee fractures. The kappa coefficient for int erpretation of the rule was 0.91 (95% CI, 0.82-1.0). Compared with non fracture patients who underwent radiography during the after-intervent ion period, those discharged without radiography spent less time in th e emergency department (85.7 minutes vs 118.8 minutes) and incurred lo wer estimated total medical charges for physician visits and radiograp hy (US $80 vs US $183). Conclusions.-Implementation of the Ottawa Knee Rule led to a decrease in use of knee radiography without patient dis satisfaction or missed fractures and was associated with reduced waiti ng times and costs. Widespread use of the rule could lead to important health care savings without jeopardizing patient care.