Detecting clinically-relevant changes in progressive multiple sclerosis.

OBJECTIVE

To investigate which changes in different clinical outcome measures contribute most to increased disease impact, as reported by the patient, in progressive multiple sclerosis (MS).

METHODS

From a cohort of prospectively-followed MS patients, we selected progressive patients with two visits, 4-6 years apart. We assessed long-term changes on the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT) and Guy's Neurological Disability Scale (GNDS). We defined the presence or absence of clinically meaningful change by using the Multiple Sclerosis Impact Scale (MSIS-29) as an anchor measure. We also studied change on recently identified sub-scales of GNDS.

RESULTS

Change on GNDS (especially the spinal-plus subscale) contributed most to increased disease impact. Also change on the T25FW contributed largely. Specific profiles of change in T25FW and MSIS seemed to exist (generally, a lower increase in disease impact in patients with longer disease duration and higher baseline impact/disability). In some patients a dissociation existed between increased impact, according to the MSIS-29, and objective physical worsening of the T25FW.

CONCLUSION

These results support using GNDS (particularly the spinal-plus domain) and T25FW in outcome measurement in progressive MS. We suggest there is a relation between baseline clinical characteristics and an increased impact at follow-up. This may have implications for patient selection in trials for progressive MS.