Validation of a Six-Item Multiple Sclerosis Impact Scale Short Form (MSIS-SF) for Efficient Assessment of Patient-Reported Physical Disturbance

ABSTRACT Patient-reported outcomes importantly reflect the lived experiences of persons with multiple sclerosis (MS); however, given the broad array of MS symptoms, comprehensive evaluation can be burdensome, especially with lengthy questionnaires. The MS Impact Scale queries twenty different physical difficulties (MSIS-20). In 1150 patients with MS, evaluation of internal consistency indicated redundancy in the MSIS-20 (Cronbach’s alpha: 0.96), but optimal internal consistency (0.90) of a six-item short form (MSIS-SF; first six MSIS items). The MSIS-20 and MSIS-SF showed comparably strong associations with objective physical disability. The MSIS-SF provides a psychometrically robust, less burdensome, and time-efficient option for assessing patient-reported physical disturbance. Competing Interest Statement The authors have declared no competing interest. Funding Statement This project was funded in part by the National Institute of Child Health and Development (NICHD) within the National Institutes of Health (NIH; R01 HD082176 to JFS). Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of the Icahn School of Medicine at Mount Sinai gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Footnotes Funding Statement: This project was funded in part by the National Institute of Child Health and Development (NICHD) within the National Institutes of Health (NIH; R01 HD082176 to JFS). Disclosures: The authors have no conflicts of interest related to the current project. Data Availability All data produced in the present study are available upon reasonable request to the authors.