RÉSUMÉ
BACKGROUND: The IADL indexes used in Korea were Korean version of Lawton Index(Lawton index), Korean instrumental activities of daily living index(K-IADL), Korean version of Bathel index(Bathel index). The purposes of this study are to compare the reliability, validity, distribution of these IADL indexes and examine the predicting ability of these measures to disability grading. METHODS: 147 patients with disability participated in the study. The patients were tested with Lawton index, K-IADL, Bathel index. The distribution, internal consistency, concurrent validity of each measures were examined. Predicting ability of these measures to disability grading was tested by comparing the mean of each measures according to Brain disability grading. RESULTS: Lawton index, K-IADL, Bathel index had acceptable and similar psychometric characteristics[high internal consistency(>0.8), high concurrent validity(Spearman's correlation coefficient, r&0.5; intraclass correlation coefficient >0.5)]. Each measures showed acceptable distribution, But K-IADL had right skewed distribution than other indexes. Predicting ability of these measures to disability grading was comparable among three IADL indexes CONCLUSION: Lawton index, K-IADL, Bathel index had acceptable and similar psychometric characteristics and discriminative ability to disability grading.