((B-143)) (B-143) Discontinuation Pattern of Disease-modifying Therapies among Older Adults with Multiple Sclerosis

Background: There is increasing debate about optimizing disease-modifying therapy (DMT) use in older adults with multiple sclerosis (MS), given their lack of proven efficacy, safety concerns, and prescription burden. Deprescribing DMTs has emerged as a critical area of interest; however, the operational definition of deprescribing remains inconsistent. Additionally, understanding trajectories of discontinuation patterns of DMT use in real-world settings among older MS patients can be valuable in generating real-world evidence for deprescribing.

Objectives: To analyze the patterns of DMT discontinuation among older adults with MS.

Methods: This retrospective cohort study included Medicare beneficiaries (≥ 65 years) with MS who used DMTs between 2011 and 2021. Eligible patients had a Proportion of Days Covered (PDC)≥ 80% for 12 months following their earliest DMT prescription and continuous Medicare Part A, B, and D enrollment but no Part C enrollment throughout the study period. PDC was assessed in each subsequent 12-month period over a total follow-up of 36 months. Descriptive analyses and visualization patterns involving the Sankey diagram were used to examine the distribution of discontinuation trends during the follow-up period.

Results: Among 64,618 aged Medicare beneficiaries with DMT use, 3,004 met the inclusion criteria. The average annual PDC (± standard deviation) during the follow-up period declined over time: 0.71 ± 0.27 (0.65-0.89 [q1-q3], median: 0.83) in the first 12 months, 0.63 ± 0.35 (0.39-0.90, median: 0.80) in the second year, and 0.55 ± 0.37 (0-0.89, median: 0.72) in the third year. After the initial identification period, 27.36% of patients maintained continuous DMT use (PDC ≥ 80%). Meanwhile, the proportion of patients with complete discontinuation (PDC = 0) increased from 6.56% in the first 12 months to 16.68% and 25.73% in the second and third years, respectively.

Conclusions: Over a three-year follow-up period, approximately one in four older adults with MS fully discontinued DMT, with a steady decline in PDC observed throughout the follow-up. More research is warranted to assess the risk-benefit profile of discontinuation of DMT among older adults with MS. Future studies should also address the effects of different discontinuation trajectories to understand the value of deprescribing practices in older adults.