Comparative value and determinants of suitability of outcome measures in treated chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION The comparative value and suitability of outcome measures are uncertain in chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS We studied 35 patients with CIDP using the Overall Neuropathy Limitation Scale (ONLS), the inflammatory Rasch-built Overall Disability Scale (I-RODS) and the Medical Research Council Sum Score (MRCSS). RESULTS Significant associations were determined between initial deficit and ONLS (p=0.002) and MRCSS improvement (p=0.001), but not I-RODS. A strong inverse correlation was observed between disease duration and I-RODS (p=0.002), but not ONLS/MRCSS improvement. A strong association was observed between age ≤40 years and I-RODS (p=0.001), but not ONLS/MRCSS improvement. Using minimum important differences, ONLS and I-RODS sensitivities were comparable (p=0.19). DISCUSSION ONLS and I-RODS are equally sensitive in identifying change. Ease of administration, better ability to detect improvement in severe disease, greater amplitude responses throughout the disease and in older subjects, favor the ONLS. The I-RODS appears more useful in early disease/younger patients. This article is protected by copyright. All rights reserved