Outcome measures in MMN revisited: further improvement needed

The objectives of the current study were to provide an overview of the outcome measures (OMs) applied in clinical trials in MMN and to determine the responsiveness of a core set of selected OMs as part of the PeriNomS study. The following OMs were serially applied in 26 patients with newly diagnosed or relapsing MMN, receiving intravenous‐immunoglobulin (assessments: T0/T3/T12 months): 14 muscle‐pairs MRC scale, the Neuropathy‐Impairment‐Scale motor‐subset, a self‐evaluation scale, grip strength, and MMN‐RODS©. All data, except the grip strength, were subjected to Rasch analyses before determining responsiveness. For grip strength, responsiveness was examined using a combined anchor‐ (SF‐36 question‐2) and distribution‐based (½xSD) minimum clinically important difference (MCID) techniques, determining the proportion of patients exceeding both identified cut‐offs. For the remaining scales, the magnitude of change for each patient on each scale was determined using the MCID related to the individual standard errors (responder definition: MCID‐SE≥1.96). Overall, a great assortment of measures has been used in MMN trials with different responsiveness definitions. For the selected OMs, responsiveness was poor and only seen in 1/4–1/3 of the patients, the grip strength being more responsive. Despite the efforts taken to standardize outcome assessment, further clinimetric responsiveness studies are needed in MMN.
Source: Journal of the Peripheral Nervous System - Category: Neurology Authors: Tags: RESEARCH REPORT Source Type: research