Perceived disease impact in patients with multiple sclerosis: associations of MSIS-29 scores with disability, medication use, and personality traits

Abstract Background Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease resulting in a substantial physical and psychological burden. Although the Expanded Disability Status Scale (EDSS) standardizes clinical disability ratings, patient-reported outcome measures (PROMs) such as the Multiple Sclerosis Impact Scale (MSIS-29) are useful for capturing the subjective disease impact from the patient perspective. However, determinants of MSIS-29 scores, particularly the role of personality traits, remain poorly understood, limiting their utility in personalized disease management. Methods In this single-center cross-sectional study, perceived disease impact was assessed in 173 patients with MS using the physical and psychological MSIS-29 subscales. Additional data were obtained from structured questionnaires and medical records. Sociodemographic, clinical, medication-related, and personality-related factors were evaluated for associations with MSIS-29 scores. Personality traits were assessed in subsets of patients using the NEO Five-Factor Inventory (NEO-FFI; n = 161) and the Temperament and Character Inventory-Revised (TCI-R; n = 150–153). Univariable and multivariable linear regression models, supplemented by moderation analyses, were applied. Results Of the 173 patients, 121 (69.9%) were women. No significant sex difference was observed in either MSIS-29 subscale, whereas older age was associated with greater physical disease impact (unstandardized β = 0.527, adjusted p = 0.002). EDSS scores were more strongly associated with physical than psychological MSIS-29 scores (unstandardized β = 7.550 vs. 2.789, both p < 0.001). A higher number of medications taken was associated with higher scores on both MSIS-29 subscales ( p < 0.001). Higher neuroticism and harm avoidance, and lower extraversion and agreeableness, were associated with greater perceived disease impact, particularly in the psychological domain (all adjusted p < 0.05). In exploratory analyses, persistence moderated the association between disability and MSIS-29 scores, with higher regression coefficients at higher levels of persistence, particularly for the psychological subscale (adjusted p = 0.042). Conclusions Patient-perceived disease impact was related not only to neurological disability and medication burden but also to personality characteristics. These findings suggest that individual differences in personality are linked to how patients experience and evaluate the consequences of MS. Integrating PROMs with traditional clinical measures may provide a more comprehensive assessment of overall disease status and facilitate a more patient-centered approach to MS care.