Development, Validation, and Internal Consistency of the Positive Psychology-Based Acceptance of Illness Scale (PAIS): A Culturally-Appropriate Japanese Measure

Acceptance of illness has been shown to improve the well-being of individuals suffering from chronic illnesses. We developed a new acceptance of illness scale, “Positive Psychology-Based Acceptance of Illness Scale: PAIS,” for HTLV-1 associated myelopathy (HAM) patients, one of the intractable neurological diseases with a chronic course. The validity and internal consistency of this PAIS were examined in 260 HAM patients in Japan. Exploratory factor analysis extracted four factors with 21 items: “Loving myself as I am”; “Experiencing the grace of illness”; “Feeling a loving connection with others”; and “Developing as a mature person”. Cronbach’s α was .83 to .88, except for Factor 4 which was slightly low at 0.64, and internal consistency was confirmed. A significant correlation was found between the PAIS and the index of convergent validity. The study’s findings are an important step toward a more comprehensive concept of acceptance of illness.