The multiple sclerosis self-concept change scale: Development and validation of a new measure

•Currently, there is no validated scale that quantifies extent and nature of self-concept change for MS populations.•This study reports on the development and validation of a new measure of self-concept change for people living with MS.•This new scale reliability and validly quantified the extent and nature of change in self-concept across five unique domains.•This new scale provides clinicians and researchers with a short and easily administered measure of self-concept change. Self-concept change may impact psychological wellbeing and functioning in people with MS (pwMS). However, the extent and nature of change in self-concept that pwMS experience is poorly understood, owing to the lack of quantitative measures available to assess this construct. To examine the factor structure, validity, and internal consistency of the newly developed Multiple Sclerosis Self-Concept Change Scale (MSSCCS). Items measuring self-concept change were created, reviewed by a panel of experts and pre-tested in a sample of 135 pwMS. A revised list of 51 items were then administered to 1307 pwMS (80.3% female; Age M = 59.21 years, SD = 11.40), together with measures of disease impact and psychosocial functioning. Exploratory factor analysis using principal axis factor extraction in 643 randomly selected participants yielded 23-items measuring 5 latent factors for the final MSSCCS. Confirmatory factor analysis involving the remaining participants supported the 5-factor model, as well as a 2nd order model of “global change”. Internal consistency of the total scale was good (α = 0.89). The MSSCCS also demonstrated evidence of concurrent and construct validity. The MSSCCS is a reliable and valid assessment, which may assist in enhancing understanding of self-concept change in pwMS.