Background Little is known about the comparative effectiveness of multiple sclerosis (MS) disease-modifying therapies (DMTs) on patient-reported outcomes in MS. We compared the effects of natalizumab to other DMTs in relation to MS symptom severity, quality of life, disability, disease progression and employment outcomes using real-world data.

Methods We included 2817 observations in 2015, 2016 and 2017 from 1382 participants in the Australian MS Longitudinal Study. Information on treatment, health and employment outcomes was prospectively collected by questionnaires. Marginal structural models with interaction terms for DMT×time were used to compare natalizumab and other comparator treatment groups.

Results Natalizumab was associated with improvements over time, or general trends of improvement, in the severity of many symptoms and work productivity loss. Compared with any other DMTs, natalizumab was associated with superior effects over time for 8 of 23 patient-reported outcomes, with similar directions of effect observed for another 6, demonstrating consistency. There were no differences in effect for spasticity, fatigue, pain, feelings of depression, disability, European quality of life five dimension index, presenteeism and work status. Natalizumab did not perform significantly worse over time compared with any other DMTs for any of the outcomes.

Conclusions Natalizumab was associated with superior outcomes over time for many patient-reported health and employment outcomes when compared with other DMTs in this large prospective cohort study. These findings may influence treatment selection in clinical practice and future treatment cost-effectiveness analyses.