炎症性腸疾患患者のQuality of Life尺度の開発

Development of A Quality of Life Assessment Scale in Patients with Inflammatory Bowel Disease

要旨

　目的：炎症性腸疾患患者のQOLを評価する尺度を開発することを目的とした．

　方法：これまでに行ってきたQOL関連要因探索研究の結果に基づき，2病院の外来患者を対象に質問紙法による調査を実施した．クロンバックのα係数および再テストによる尺度の信頼性と，因子分析による構成概念妥当性および外的基準との相関係数による基準関連妥当性を検証した．

　結果：質問紙を460部配布し，分析対象は319名（クローン病222名，潰瘍性大腸炎97名）であった（有効回答率69.3％）．項目分析と探索的因子分析により19項目5因子を抽出した．19項目に欠損がない対象300名のクロンバックのα係数は尺度19項目全体が .914，因子別では .710〜 .927の範囲であった．再テスト法の級内相関係数は .820，外的基準との相関係数は，SF-8のPCSが .388，MCSが .711，生活満足度10点評価が .731であった．

　結論：信頼性，妥当性は概ね良好であったが，構成概念妥当性については課題が残った．

　Aims: This study aimed to develop a scale for quality of life (QOL) assessment in patients with inflammatory bowel disease.

　Methods: Based on the results of our previous exploratory studies on factors associated with QOL, a survey was conducted among outpatients in two hospitals using a questionnaire. Reliability of the scale was verified by Cronbach's coefficient alpha and retesting, construct validity by factor analysis, and criterion-related validity by correlation coefficient with the external criterion.

　Results: A total of 460 questionnaires were distributed, and 319 participants (222 patients with Crohn's disease and 97 patients with ulcerative colitis) were analyzed (69.3% effective response rate). Using item analysis and exploratory factor analysis, 19 items and five factors were extracted. Cronbach's coefficient alpha for 300 participants with no missing values for the 19 items was .914, and it was within the range of .710 to .927 by factor. The intraclass correlation coefficient of retesting was .820. The correlation coefficient with the external criterion was .388 for the physical component summary and .711 for the mental component summary of the short-form 8. It was .731 for the 10-point scale life satisfaction ratings.

　Conclusion: The results showed that overall reliability and validity of the scale were good; however, there were still unresolved issues with construct validity.