Age-related decreases in relapses among adults with relapsing-onset multiple sclerosis

Area of Science:

• Neurology
• Immunology
• Epidemiology

Background:

• Relapsing-onset multiple sclerosis (MS) typically affects young to middle-aged adults.
• The long-term disease activity trajectory, particularly age-related changes in relapse rates, remains incompletely understood.
• Previous research has not adequately quantified the age-specific contribution to decreases in annualized relapse rates (ARR).

Purpose of the Study:

• To quantify the age-specific component of decreases in ARR over time in adults with relapsing-onset MS.
• To differentiate the impact of aging versus disability worsening on ARR.
• To model these changes under various clinically relevant assumptions.

Main Methods:

• Utilized simulation modeling to explore changes in ARR.
• Assessed the influence of age and disability status on ARR.
• Incorporated data from British Columbia MS patients and literature reviews to inform model parameters.

Main Results:

• Demonstrated a substantial age-specific decrease in ARR across all simulated scenarios.
• Found that 88%-97% of the ARR decrease was attributable to age, with only 3%-13% attributed to disability worsening.
• Quantified age-specific ARR decreases ranging from 22% to 37% per 5 years for a broad spectrum of initial ARR.

Conclusions:

• Age is the primary driver of decreased relapse activity in relapsing-onset MS, more so than disability progression.
• Understanding the dynamic relationship between age and MS relapses is crucial for informed clinical decision-making.
• These findings highlight the importance of considering age in managing MS patients over their lifetime.