The psychometric properties of the Persian version of the Multiple Sclerosis Self-Management Scale-Revised: A cross-sectional methodological study

Backgrounds and Aims: Patients with multiple sclerosis (pwMS) need self -management (SM) skills to manage their symptoms and problems. An essential step to SM improvement is accurate SM assessment using valid and reliable instruments. The aim of this study was to evaluate the psychometric properties of the Persian version of the Multiple Sclerosis Self-Management Scale-Revised (MSSMS-R). Methods: This cross-sectional methodological study was conducted from December 2021 to June 2022. The face, content, and construct validity of MSSMS-R were evaluated. Construct validity was evaluated through confirmatory factor analysis (CFA) and evaluating convergent and discriminant validity using the data obtained from 210 randomly selected MS patients. The reliability of the scale was also evaluated through the test-retest stability and the internal consistency evaluation methods. Results: The face validity was confirmed and the content validity ratio and index values of all items were more than 0.62 and 0.79, respectively. CFA revealed the acceptable construct validity of the scale after omitting items 21 and 22. In convergent and discriminant validity evaluation, the total score of MSSMS-R had significant positive correlation with the total mean scores of the Multiple Sclerosis Self-Efficacy Scale (r = 0.36; p < 0.001) and the physical health composite (r = 0.31; p < 0.001) and the mental health composite (r = 0.39; p < 0.001) dimensions of the 54-item Multiple Sclerosis Quality of Life scale and significant inverse correlation with the total mean score of the Beck Depression Inventory (r = -0.28; p < 0.001). The Cronbach's alpha values of the scale and its subscales were 0.86 and 0.65-0.90 and their test-retest intraclass correlation coefficients were 0.97 and 0.95-0.99, respectively. Conclusion: The Persian MSSMS-R is a valid and reliable scale and can be used in future studies for SM assessment among pwMS.