Psychometric properties of the Chinese version of Arthritis Self-Efficacy Scale-8 (ASES-8) in a rheumatoid arthritis population

The Arthritis Self-Efficacy Scale-8 (ASES-8) is a valid tool to measure patients' arthritis-specific self-efficacy. However, evidence about reliability and validity of the ASES-8 in Chinese arthritis patients is lacking. This study aimed to culturally adapt and test the psychometric properties of the Chinese version of the ASES-8. Chinese ASES-8 was translated from original English version using translation and back-translation procedures. Validation survey was then conducted in a university-affiliated hospital by a set of questionnaires comprised Chinese ASES-8, pain-VAS, The Hospital Anxiety and Depression Scale (HADS), Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F), and Short Form 36-Item Health Survey (SF-36) physical functioning subscale. A convenience sample of 134 patients with rheumatoid arthritis was recruited from the department of rheumatology. Validity was assessed by Pearson's correlation analysis and exploratory factor analysis. Reliability was assessed using the intra-class correlation coefficient (ICC) and Cronbach's alpha. Exploratory factor analysis extracted one dimension that explained of the 71.35% variation. Significant negative correlations were found between the ASES-8 and pain-VAS, HADS-D, HADS-A scores (r -0.487 to -0.656, p < 0.01), while positive correlations were found between the ASES-8 and SF-36 PH (r = 0.561, p < 0.01), FACIT-F (r = 0.660, p < 0.01). Excellent test-retest reliability (ICC = 0.98) and internal consistency (Cronbach's alpha = 0.942) were demonstrated. The Chinese version of the ASES-8 had statistically acceptable levels of reliability and validity for assessing self-efficacy in patients with rheumatoid arthritis. This disease-specific scale is particularly valuable for use among patients with rheumatoid arthritis from the Chinese population.