急性期統合失調症の作業遂行能力客観評価尺度の開発とその信頼性と妥当性

Development, reliability and validity of the Occupational Performance Scale (OPS) to assess acute schizophrenia

要旨：急性期統合失調症患者を対象とした簡易に使用できる『作業遂行能力客観評価尺度(以下，OPS)』を作成した．OPSの信頼性と妥当性について，統合失調症圏患者126名を対象として検討した．その結果，尺度の内的一貫性と再テスト信頼性は高く，評価者間信頼性は良好であった．OPSと簡易精神症状評価尺度(BPRS)，機能の全体的評定尺度(GAF)との相関係数はそれぞれ0.46，-0.58であり，関連性は良好であった．OPSの退院時得点は作業療法開始時に比べ有意に改善しており応答性も良好であった．OPSは急性期統合失調症患者に対して，簡便に繰り返し使用できる信頼性と妥当性のある尺度であることが示唆された．

　Objective: We developed a brief scale to assess occupational performance in patients with acute schizophrenia.

　Method: The Occupational Performance Scale (OPS) consists of six items : physical fatigue, stability of mood, interpersonal fatigue, interest, occupational performance skills, and interpersonal skills, each having five grade levels. One hundred twenty-six patients with schizophrenia or schizophreniaspectrum disorders participated in this study. These patients were evaluated with the OPS, the Brief Psychiatric Rating Scale (BPRS) and the Global Assessment of Functioning (GAF).

　Results: The OPS scale showed excellent internal consistency (Cronbach's a coefficient = 0.88), excellent test-retest reliability (r=0.67〜0.85, by Spearman's rank coefficients test), and a good inter-rater reliability (r = 0.42〜0.75). We found a significant correlation between OPS and BPRS (r =0.46) and a significant negative correlation between OPS and GAF (r= -0.58). The improvement in OPS was significantly associated with that in BPRS and GAF (r = 0.20 and -0.59, respectively).

　Conclusion: These findings suggest that OPS is a reliable and valid tool for assessing various phases of schizophrenia. The OPS might be useful for brief assessments of patients' occupational performance in psychiatric occupational therapy settings.