Adherence and persistence to drug therapies for multiple sclerosis: A population-based study

Area of Science:

• Neurology
• Pharmacology
• Public Health

Background:

• Adherence and persistence to disease-modifying therapies (DMT) are crucial for managing multiple sclerosis (MS).
• Previous studies on DMT adherence in MS have often focused on non-population-based cohorts, potentially limiting generalizability.
• Understanding adherence predictors is vital for optimizing treatment outcomes in chronic neurological conditions.

Purpose of the Study:

• To estimate the prevalence of optimal adherence and persistence to DMT in MS patients across three Canadian provinces.
• To identify predictors associated with optimal adherence and persistence to MS DMT.
• To compare adherence rates with those reported for other chronic diseases and MS cohorts.

Main Methods:

• Utilized population-based administrative databases from British Columbia, Saskatchewan, and Manitoba.
• Included individuals receiving specific DMTs (interferon-β-1b, interferon-β-1a, glatiramer acetate) within defined timeframes.
• Assessed one-year adherence using Proportion of Days Covered (PDC ≥80%) and persistence via time to DMT discontinuation; employed regression models and meta-analysis.

Main Results:

• An estimated 76.4% of 4830 included individuals achieved optimal adherence (PDC ≥80%).
• Median time to initial DMT discontinuation varied by province, ranging from 1.9 to 4.0 years.
• Increased physician visits (≥4) in the prior year were associated with higher optimal adherence; age, sex, and socioeconomic status showed no association.

Conclusions:

• Adherence to MS DMTs in this population-based study exceeded rates reported for other chronic diseases and non-population-based MS cohorts.
• Further research into the factors driving better adherence in MS and its impact on disease outcomes is warranted.
• Findings offer insights for improving the management of MS and potentially other chronic conditions.