Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29)
Melina Ramp; Fary Khan; Rose Anne Misajon; Julie Pallant
BACKGROUND: Multiple Sclerosis (MS) is a degenerative neurological disease that causes impairments, including spasticity, pain, fatigue, and bladder dysfunction, which negatively impact on quality of life. The Multiple Sclerosis Impact Scale (MSIS-29) is a disease-specific health-related quality of life (HRQoL) instrument, developed using the patient's perspective on disease impact. It consists of two subscales assessing the physical (MSIS-29-PHYS) and psychological (MSIS-29-PSYCH) impact of MS. Although previous studies have found support for the psychometric properties of the MSIS-29 using traditional methods of scale evaluation, the scale has not been subjected to a detailed Rasch analysis. Therefore, the objective of this study was to use Rasch analysis to assess the internal validity of the scale, and its response format, item fit, targeting, internal consistency and dimensionality....
Melina Ramp, Fary Khan, Rose Anne Misajon, & Julie Pallant (2009). Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29). Health and Quality of Life Outcomes, 7(1), 58-58. https://doi.org/10.1186/1477-7525-7-58