Comparing the NIS vs MRC and INCAT sensory scale through Rasch analyses

Abstract
We performed a comparison between NISsensory versus the mISS, and NISmotor versus the MRCsumscore in patients with Guillain‐Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and IgM monoclonal gammopathy of undetermined significance related polyneuropathy (MGUSP).
The ordinal data were subjected to Rasch analyses, creating Rasch‐transformed (RT)‐intervals for all measures. Comparison between measures was based on validity/reliability with an emphasis on responsiveness (using the patient's level of change related to the individually obtained varying standard errors for minimum clinically important difference (MCID‐SE)). Eighty stable patients (GBS: 30, CIDP: 30, MGUSP: 20) were assessed twice (entry: 2‐observers; 2‐4 weeks later: 1‐observer), and 137 newly diagnosed or relapsing patients (GBS: 55, CIDP: 59, IgM‐MGUSP: 23) were serially examined with 12 months follow‐up.
Data modifications were needed to improve model fit for all measures. The sensory and motor scales demonstrated approximately equal and acceptable validity and reliability scores. Responsiveness scores were poor but slightly higher in RT‐mISS compared to RT‐NISs. Responsiveness was equal for the RT‐motor scales, but higher in GBS compared to CIDP; responsiveness was poor in patients with MGUSP, suggesting a longer duration of follow‐up in the latter group of patients.

Source: Journal of the Peripheral Nervous System - March 1, 2015 Category: Neurology Authors: Thomas H.P. Draak, Els K. Vanhoutte, Sonja I. van Nes, Kenneth C. Gorson, W. Ludo Van der Pol, Nicolette C. Notermans, Eduardo Nobile‐Orazio, Jean‐Marc Léger, Peter Y.K. Van den Bergh, Giuseppe Lauria, Vera Bril, Hans Katzberg, Michael P.T. Lunn, Jea Tags: RESEARCH REPORT Source Type: research