Research Article Psychometric Properties of the 8-Item English Arthritis Self-Efficacy Scale in a Diverse Sample

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Arthritis self-efficacy is important for successful disease management. This study examined psychometric properties of the 8-item English version of the Arthritis Self-Efficacy Scale (ASES-8) and differences in ASES-8 scores across sample subgroups. In 401 participants with self-reported doctor-diagnosed arthritis, exploratory factor analysis and tests of internal consistency were conducted. Concurrent validity was examined by associating ASES-8 scores with disease-specific, psychosocial, functional, and behavioral measures expected to be related to arthritis self-efficacy. All analyses were conducted for the full sample and within subgroups (gender, race, age, education, and weight status). Exploratory factor analysis for the entire sample and in all 12 subgroups demonstrated a one factor solution (factor loadings: 0.61 to 0.89). Internal consistency was high for measures of Cronbach’s alpha (0.87 to 0.94), omega (0.87 to 0.93), and greatest lower bound (0.90 to 0.95). ASES-8 scores were significantly correlated with all measures assessed