The Phenotypes of Multiple Sclerosis Differ Significantly in Relative and Excess Mortality

Area of Science:

• Neurology
• Epidemiology
• Public Health

Background:

• Multiple Sclerosis (MS) is associated with increased mortality compared to the general population.
• Understanding mortality differences across MS subtypes is crucial for patient care and resource allocation.

Purpose of the Study:

• To compare relative and excess mortality between Primary Progressive MS (PPMS), relapsing Onset MS (ROMS), and Secondary Progressive MS (SPMS).
• To analyze mortality risks across different MS disease courses.

Main Methods:

• Utilized the Danish MS Registry (1994-2022) including 14,120 MS patients.
• Compared excess and relative mortality adjusting for sex, age, treatment, and relapses.
• Calculated adjusted mortality ratios between MS phenotypes.

Main Results:

• PPMS and ROMS exhibited similar long-term excess mortality.
• Secondary Progressive MS (SPMS) demonstrated significantly higher relative (6.05x) and excess (1.90x) mortality compared to PPMS.
• Data included 1412 PPMS, 12,449 ROMS cases, with 627 deaths.

Conclusions:

• PPMS and ROMS have comparable mortality risks.
• SPMS carries a substantially higher mortality burden, likely due to accumulated disease effects.
• Highlights the need for advanced treatment strategies and comorbidity management in later MS stages.