「作業に関する自己評価・改訂版」の信頼性および基準関連妥当性に関する研究—作業療法学生を対象として

A study of the reliability and criterion-related validity of the Japanese version of Occupational Self Assessment version 2 in occupational therapy students

要旨：作業療法学生98名を対象に作業に関する自己評価日本語版(以下，OSA Ⅱ)の信頼性とQOL基準関連妥当性を検証した．Cronbachのα係数と再試験法で信頼性を，健康関連QOL評価のSF-36との相関で基準関連妥当性を検討した．OSAⅡ下位項目の環境の作業有能性尺度以外で高い内的整合性を，再試験では全項目で有意な相関を示した．OSA Ⅱ遂行領域の作業有能性尺度の多くがSF-36の5つのサブスケールと有意な相関を示した．作業遂行の変動しやすさを考慮するとOSA Ⅱは実用的な信頼性があり，OSA Ⅱ遂行領域の作業有能性尺度はSF-36と関連し，習慣化および意志領域は医療行為が直接介入できない作業療法独自のQOL評価視点と考えられた．

　We evaluated 98 occupational therapy students by inspecting the reliability and QOL criterionrelated validity of the Japanese version of the Occupational Self Assessment version 2 (OSA Ⅱ). We validated the reliability by using Cronbach's alpha and a test-retest method at intervals of two weeks, and the QOL criterion-related validity between OSA Ⅱ and SF-36 by using Spearman's rank correlation coefficient.

　The results showed that there was a high internal consistency in OSA Ⅱ, except for the Occupational Competence Scale of Environment, and that all items of OSA Ⅱ were significant according to the test-retest correlations (Spearman's rank correlation). In addition, the results indicated that most of these correlations were moderate, and that there were significant correlations between OSA Ⅱ and 5 subscales of SF-36, which were concentrated in the Occupational Competence Scale of performance area in OSA Ⅱ.

　The above results imply it is possible that OSA Ⅱ has satisfactory reliability when considering changeable human occupations, and the Occupational Competence Scale of performance area in OSA Ⅱ correlates especially well with health-related QOL, and the habituation and volition areas in OSA Ⅱ are unique perspectives of QOL measurement in Occupational Therapy.