Abstract Details

Title Responder Definition of the Multiple Sclerosis Impact Scale (MSIS-29) Physical Impact Scale for Patients with Physical Worsening

Topic MS and Related Diseases

Presentation(s) P01 - (-)

Poster/Presentation
Number 207

Objective

Background BACKGROUND: The MSIS-29 was developed to examine the impact of MS on physical and psychological functioning from a patient's perspective. It is frequently used in MS clinical trials, yet the RD for this endpoint has not been determined among clinical trial patients.

Design/Methods DESIGN/METHODS: Data were derived from SELECT, a multicenter efficacy study of daclizumab HYP in RRMS (N=600; baseline: mean age 35.8 years, EDSS 2.7 [range 0-5]). Both anchor- and distribution-based approaches were used to estimate MSIS-Physical RD. Anchor-based estimates were based on EDSS-confirmed disability progression (primary anchor of interest) and published RD values for worsening of the EQ-5D utility index and visual-analogue scales, and SF-12 Physical Component Summary score. Mean and median change scores in MSIS-Physical at 12, 24, and 52 weeks among those who met anchor-specific pre-defined thresholds for change were used to determine RD. Distribution-based estimates were based on Standard Error of Measurement (SEM) and two levels of change score effect size (ES), 0.3 and 0.5.

Results RESULTS: Anchor-based approaches yielded mean, median, and mode RD values of 6.91, 7.14, and 7.50, respectively (range 3.75-9.48). Distribution-based RD estimates were 8.05 (SEM), 6.24 (ES=0.3), and 10.40 (ES=0.5). With this evidence, and knowing that the MSIS Physical scores changes in increments of 1.25 points, a change of 7.5 points was selected as the most appropriate RD threshold for physical worsening, and is consistent with the RD resulting from the anchor of confirmed disability progression.

Conclusions CONCLUSIONS: Based on this analysis, a change of 7.5 points on the MSIS-Physical represents the best estimate of the RD for patients with physical worsening. This finding will be useful for assessing treatment efficacy and for powering MS clinical studies.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
Jacob S. Elkins, MD	No disclosure on file
Norman Putzki, MD (Novartis Pharma AG)	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file

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