日本語版職業コミットメント尺度の信頼性・妥当性の検討

Reliability and Validity of the Japanese Version of the Occupational Commitment Scale

要旨

目的：北米で作成された職業コミットメント尺度（OCS）を日本語に翻訳し，日本語版OCSの信頼性と妥当性を検証した．

対象と方法：看護師を対象とした予備調査において尺度の信頼性と因子構造を確認後，看護師4046名を対象に本調査を実施し，1331名（有効回答率32.9％）を分析対象とした．

結果：探索的因子分析により，情緒的職業コミットメント，功利的職業コミットメント，規範的職業コミットメントの3因子が抽出され，確証的因子分析で良好な適合度が得られた．信頼性係数は尺度全体が0.817，下位尺度が0.756〜0.837であり，I-T相関はおおむね良好な値が得られた．併存妥当性の基準とした職務満足感とは有意な正の相関が，離職意向とは有意な負の相関が認められた．

結論：1項目のみ日本語訳の信頼性，妥当性が十分に得られず，結果の解釈に留意が必要であるものの，日本語版OCSについて，一定の信頼性，構成概念妥当性および併存妥当性が確認された．

Purpose: The purpose of this study is to translate the Occupational Commitment Scale into Japanese, and examine its reliability and validity.

Methods: We developed a Japanese version of the Occupational Commitment Scale consisting of 18 items. We then tested its reliability and validity in a pilot study among nurses. As predicted, the results indicate that the three-factor structure of the scale (affective occupational commitment, continuance occupational commitment, and normative occupational commitment) is suffi-ciently reliable. Subsequent to testing, we mailed self-administered questionnaires to 4046 nurses in Japan, and analyzed 1331 (32.9%) of the responses we received.

Results: As with the original scale, three factors were extracted by factor analysis, but one item was excluded from the scale due to insufficient factor load. Confirmatory factor analysis indicated a 3-factor model was valid for the 17-item scale (GFI=0.946, AGFI=0.925, CFI=0.929, RMSEA=0.060). Cronbach's alpha coefficients of the scale and its three subscales were 0.690-0.837. Internal consistencies were confirmed by item-total correlation, resulting in one item's exclusion. Concurrent validity was supported by positive correlations of the three subscales with job satisfaction, and negative correlations with intention to leave nursing.

Conclusion: While further studies are needed to confirm the reliability and validity of one item, this study's results indicate that the Japanese version of the Occupational Commitment Scale has acceptable reliability and construct validity.