EFFECTS OF BINARY DECISION-MAKING ON THE CLASSIFICATION OF FRACTURES OF THE ANKLE

Objective: To evaluate the effect of binary decision making on interob server reliability in the classification of fractures of the ankle. De sign: Radiographic review study. Patients/Participants : Observers: tw o PGY-2 orthopaedic residents, two PGY-5 residents, and two orthopaedi c attending surgeons. Intervention: Radiographs of fifty ankle fractur es were classified. Each observer classified the radiographs by using the original AO/ASIF system and its recent binary modification. Main O utcome Measurements: Interobserver reliability was assessed by using a kappa coefficient and compared for the two classification methods. Re sults: The mean kappa value for interobserver reliability for type onl y and for type and group classification when using the original AO/ASI F system was 0.77 and 0.61, respectively. Using binary decision making , the mean kappa values for type only and for type and group were 0.78 and 0.62, respectively. There was no statistically significant differ ence in reliability between the original and binary classification sys tems. Conclusion: The interobserver reliability of both the original A O/ASIF classification system and its binary modification is substantia l. The results of the present study, however, cast doubt on the effect iveness of binary decision making in improving interobserver reliabili ty in the classification of fractures. To our knowledge, this study is the first to compare the original AO/ASIF classification system with its binary modification. Additional study of other fractures may help elucidate the effectiveness of binary decision making in improving int erobserver reliability in the classification of all fractures.