Can the ICF be used as a rehabilitation outcome measure? A study looking at the inter- and intra-rater reliability of ICF categories derived from an ADL assessment tool.

PURPOSE: The categories of the International Classification of Functioning , Disability and Health (ICF) could potentially be used as components of outcome measures. Literature demonstrating the psychometric properties of ICF categories is limited. OBJECTIVE: Determine the agreement and reliability of ICF activities of daily living category scores and compare these to agreement and reliability of the Functional Independence Measure (FIM) item scores. METHOD: Two investigators independently reviewed the clinical notes to score the ICF activities of daily living cate-gories, of 100 patients using ICF qualifiers with additional scoring guidelines. The percentage agreement, interrater and intrarater reliability were compared with the matched FIM items scored by a separate set of two investigators using the same methodology. Kappa Statistic was calculated using Med Calc. RESULTS: ICF interrater reliability as indicated by Kappa values ranging from 0.42 to 0.81 was moderate or better for the eleven self care and mobility categories. The language ICF categories and problem solving generally have fair agreement, with Kappa values ranging from 0.21 for receiving verbal messages to 0.44 for basic social interactions. Absolute agreement was above 72% for all categories. Reliability and agreement of the FIM items was generally lower than the corresponding ICF categories. CONCLUSION: The inter-rater and intra-rater reliability and agreement of the ICF activities of daily living categories were comparable or better than the corresponding FIM items. The results of this study provide an indication that the ICF categories could be used as components of rehabilitation outcome measures.