Association Between Measures of Disability and Employment in Secondary Progressive Multiple Sclerosis: Baseline Data from the ASCEND Natalizumab Trial

Background: Disability in multiple sclerosis (MS) has been shown to impact multiple aspects of patients’ lives including employment status. ASCEND is an ongoing international, Phase 3b, randomized, double-blind, placebo-controlled study to evaluate whether natalizumab reduces disability progression unrelated to relapses in patients with secondary progressive MS (SPMS).

Objectives: To investigate differences in clinical or patient-reported outcomes by employment status in SPMS patients randomized into the ASCEND trial.

Methods: Subjects with SPMS were randomized 1:1 to treatment with natalizumab or placebo for 2 years. At enrollment, detailed information on employment was obtained from all subjects. Neurological assessments include measures of walking ability (T25FW, MSWS-12, 6MWT), hand dexterity (ABILHAND, 9HPT), physical disability (EDSS), and cognitive impairment (SDMT for all subjects and a novel composite endpoint based on SDMT, SRT, BVMTR, and PASAT for a subgroup of participants). Associations between employment status (full-time/part-time or unemployed) and baseline disability outcome measures were evaluated using pooled blinded subject data and stratified by standard demographic variables (age, gender, level of education) and employment.

Results: At baseline, 339 of the 889 (38%) SPMS patients enrolled in ASCEND were employed (29% outside the home, 3% at home, 6% homemakers, <0.5% students) while 550 (62%) were unemployed. At baseline, unemployed subjects had significantly longer T25FW times, worse MSWS-12 scores, and worse EDSS scores than employed subjects (all P<0.0001). Employed subjects at baseline had better 6MWT distance, better ABILHAND, 9HPT, and SDMT scores, and, in the cognitive impairment composite endpoint subgroup, better composite cognition endpoint z-score than unemployed subjects. There was no significant difference in age between unemployed (mean 47.5y) and employed (mean 46.7y) subjects. A significantly higher percentage of employed subjects were married (70.1% vs 60.7% unemployed) and had more years of education (mean 13.8y vs 12.9y unemployed).

Conclusions: Strong associations were found at baseline between unemployment and worse physical and cognitive disability outcomes in the ASCEND study.