成人型アトピー性皮膚炎患者の痒みに対する不安尺度の開発 : 信頼性・妥当性の検討  [in Japanese] Development of the Itch Anxiety Scale for Atopic Dermatitis(IAS-AD) : Reliability and Validity  [in Japanese]

本研究の目的は,成人型アトピー性皮膚炎患者が訴える痒みに対する不安を測定するItch Anxiety Scale for Atopic Dermatitis (IAS-AD)を開発し,その信頼性と妥当性を確かめることであった.大学生294名,およびアトピー性皮膚炎を罹患する大学生44名を対象に自記式の調査を行い,探索的因子分析を行ったところ,IAS-ADは「環境誘発型」「ストレス誘発型」の2因子17項目で構成された.各因子の内的整合性は高かった(α=0.88〜0.91).また,IAS-ADはアトピー性皮膚炎に罹患している大学生とそうでない大学生を判別することが可能であり,アトピー性皮膚炎罹患の有無を予測することが可能であった.また,IAS-ADはSTAI-JYZとは異なる不安を測定することが明らかになった.以上の結果から,IAS-ADは高い信頼性と妥当性を有することが明らかになった.

Objective : Atopic dermatitis (AD) is a chronic skin disorder. AD often develops between infancy and adolescence, runs a course of remissions and exacerbations. Originally, AD is child's skin disease. However, the number of AD patients is increasing. Adult AD patients generally show a high anxiety level. It is indicated that anxiety in adult patients causes high rate of scratching behavior. However, not much research on the anxiety to itch has been conducted enough in adult AD patients. The purpose of this study is to develop the Itch Anxiety Scale for Atopic Dermatitis (IAS-AD) to assess the anxiety to itch in adult AD patients. Method : The participants of this study were 294 undergraduate students. Forty-four undergraduate students were diagnosed as atopic dermatitis. The participant of this study completed the IAS-AD, the State-Trait Anxiety Inventory-form JYZ (STAI-JYZ), and the level of subjective itch by using Visual Analogue Scale (VAS). Results : Result of exploratory factor analysis revealed that the IAS-AD consisted of 17-items loading on two factors, which were named "Environmentally-induced type" and "Stress-induced type". Internal consistency of each factor was sufficiently high (α = 0.88-0.91). Result of t test revealed that undergraduate students with atopic dermatitis showed higher scores than healthy students in IAS-AD. In addition, a result of logistic regression analysis revealed that the IAS-AD predicted the morbidity of AD. Furthermore, for setting the cut-off point, ROC curve (Receiver operating characteristic curve) was calculated. Result of ROC analysis indicated that sensitivity and specificity were at their maximum when IAS-AD score was 37.5point. Therefore, the point of 37 was adopted as the cut-off point. Conclusion : It was concluded that the IAS-AD have high internal consistency and validity. It was suggested that the IAS-AD have potential significance for the clinical and research application. Finally, discussion was made on about IAS-AD with respect to severity of symptoms.