The patient knows best: significant change in the physical component of the Multiple Sclerosis Impact Scale (MSIS-29 physical)

Abstract

Aim: The aims of this study were to determine the reliability, responsiveness and minimally important change score of the Multiple Sclerosis Impact Scale (MSIS)-29 physical using the Expanded Disability Status Scale (EDSS) as an anchor measure. Methods: 214 patients with multiple sclerosis (MS) (EDSS 0-8.5) had concurrent MSIS-29 and EDSS assessments at baseline and at up to 4 years of follow-up. Results: 116 patients had unchanged EDSS scores. Stability of the MSIS-29 physical (mean change 0.1 points) was better in the 85 patients with EDSS 0-5.0 than in the 31 patients with EDSS 5.5-8.5 in whom the MSIS-29 physical score fell by 8 points, a response shift phenomenon. A floor effect for the MSIS-29 was observed in 5% of stable patients at both time points. 98 patients experienced EDSS change with moderately strong statistically significant correlations between change scores in the EDSS and the MSIS-29 physical (r = 0.523, p,0.0001). Effect sizes for MSIS-29 physical change were moderate to large. Using receiver operating characteristic curves, the MSIS-29 change score which produced a combination of optimal sensitivity and specificity was chosen for both EDSS ranges. For EDSS range 5.5-8, a change score of 8 had a sensitivity of 87% and specificity of 67%. For EDSS 0-5.0, a change score of 7 had a sensitivity of 78% and a specificity of 51%. Conclusions: The MSIS-29 physical performs well over time, and is suitable for use in trials; a minimal change score of 8 points in the MSIS-29 is clinically significant.

Do patient and proxy agree? Long-term changes in multiple sclerosis physical impact and walking ability on patient-reported outcome scales

“…25 Furthermore, because the MSWS is restricted to patients who can walk, individuals were instructed to complete the scale only when the patient was able to walk. Instructions were not always well understood, however, and some patients or proxies completed the scale with an (almost) maximum score while their partners did not complete the MSWS because the patient could not walk.…”

Outcome Measurement in Neurodegenerative Disease: Attributes, Applications & Interpretation

“…The psychometric properties of the MSIS-29 have been widely reported and it is regarded as a highly reliable, valid and responsive instrument [66,67,[69][70][71][72]. The measure has been increasingly utilized in research and clinical settings, including in randomized controlled trials [73][74][75][76] and studies relating to, for example, cognitive behavioral therapy [77], patient education [78], exercise [79,80] and fatigue [81].…”

Disease progression in multiple sclerosis: combining physicians’ and patients’ perspectives?

“…9,17 For the MSIS physical, a change of 8 points was used as cut-off, based on a recently performed study. 18 With respect to detecting disease progression on a certain outcome measure, we defined three conditions. First, a worsening on that measure irrespective of the change on the other measures (referred to as 'total worsening').…”