変形性膝関節症患者のセルフケア能力尺度の開発

Self-Care Agency in Patients with Primary Osteoarthritis of the Knee: Scale Development

要旨

　目的：変形性膝関節症患者（以下，膝OA患者とする）に特化したセルフケア能力を評価できる指標を開発することである．

　方法：一次性膝OA患者を対象とした．項目分析，確証的因子分析を用いた構成概念妥当性の検討により尺度を構築し，信頼性，基準関連妥当性の検討を行った．

　結果：分析対象は386名であった．分析の結果，5因子20項目モデルが構築された（GFI＝0.927, AGFI＝0.907, CFI＝0.919, RMSEA＝0.045）．「自己の病気および状況に関心を持ち把握する力」「療養法を遵守し継続していく力」「関節への負担軽減のために生活の仕方を調整する力」「病状悪化予防のために能動的に情報・方略を取り入れていく力」「有効な支援を希求し活用する力」の各因子4項目から成る「膝OA患者のセルフケア能力尺度」が作成された．尺度のCronbach'sは0.813で，外的基準とも有意な関連性が認められた．

　結論：尺度の構成概念妥当性および基準関連妥当性，信頼性が確認され，開発した尺度は膝OA患者のセルフケア能力を適切に測定できる可能性が示唆された．

　Purpose: The aim of this study was to develop an instrument to assess self-care agency in patients with primary osteoarthritis of the knee.

　Method: The participants consisted of 386 patients with osteoarthritis of the knee. Scale development involved several phases, including item development, reliability testing, criterion-related validity testing, and construct validity testing.

　Results: Confirmatory factor analysis was conducted in order to assess the extent to which the Self-Care Agency in Patients with Knee Osteoarthritis Scale (SCAKOS) structure fit the present data. The fit indices were approximately satisfactory (GFI＝0.927, AGFI＝0.907, CFI＝0.919, RMSEA＝0.045). The SCAKOS comprises five factors with 20 items. All standardized coefficients in the model were moderate to high and all t-values were acceptable (p＜0.01). The factors are as follows: “ability to acknowledge and understand the disease and its severity,” “ability to adhere to a treatment strategy,” “ability to modify daily life to reduce load on the knees,” “ability to proactively adopt information and methods useful for preventing disease exacerbation,” and “ability to seek effective support and apply it to improving quality of life.” Cronbach's alpha for the total SCAKOS score was 0.813. The SCAKOS score was correlated significantly with SCAQ score and self-care one's health score (p＜0.01).

　Conclusion: We developed the SCAKOS to measure self-care agency in patients with primary osteoarthritis of the knee. These findings suggest that the scale is suitable for model building, and can also be effectively used to assess self-care agency in patients with knee osteoarthritis, particularly those in Japan.