Related Experiment Video
Updated: Dec 25, 2025
A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Disease-Modifying Therapy Adherence and Associated Factors in a National Sample of Medicare Patients With Multiple
Pengxiang Li1, Vrushabh P Ladage1, Joseph Berger1
1Division of General Internal Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Objectives:
Disease-modifying therapies (DMTs) reduce relapse rates and disability progression for relapsing multiple sclerosis (MS). Although 25% to 30% of all US patients with MS are Medicare beneficiaries, limited information exists on this population. This is the first study using national Medicare data to (1) describe characteristics of patients with MS using DMTs, (2) estimate adherence to DMTs over a 1-year and 3-year follow-up, and (3) examine factors associated with DMT adherence.
Methods:
This retrospective claims analysis used 2011-2014 100% Medicare files. Monthly adherence to MS DMTs was defined as the proportion of days covered ≥0.80 with any DMT in each month for 1-year (n = 36 593) and 3-year (n = 17 599) follow-up samples of MS DMT users. Generalized estimating equation logistic regressions were used to estimate factors associated with adherence to DMTs.
Results:
Over 90% of patients were eligible for Medicare owing to disability, and about three-quarters qualified for low-income subsidies. A downward trend in DMT adherence was observed over time in both samples. Monthly adherence dropped significantly between December of the prior year to January of the following year (from 76% to 65% in the 1-year follow-up sample and similar drops seen across all years in the 3-year follow-up sample). Multivariable regressions indicated characteristics such as being low-income, having a disability, and having high patient out-of-pocket DMT costs associated with poor adherence to DMTs.
Conclusion:
Our study provides important insights into the characteristics and DMT adherence of Medicare patients with MS and highlights the need for interventions and policies mitigating barriers to adherence in this population.
Insights
Medicare patients with multiple sclerosis (MS) show declining adherence to disease-modifying therapies (DMTs) over time. Low income, disability, and high out-of-pocket costs are linked to poor DMT adherence in this population.
Area of Science:
- Neurology
- Health Services Research
- Pharmacoeconomics
Background:
- Disease-modifying therapies (DMTs) are crucial for managing relapsing multiple sclerosis (MS), reducing relapses and disability.
- Medicare beneficiaries represent a significant portion (25-30%) of US patients with MS, yet data on their DMT use is limited.
Purpose of the Study:
- To characterize Medicare patients with MS who use DMTs.
- To estimate DMT adherence rates over 1- and 3-year periods in this population.
- To identify factors associated with DMT adherence among Medicare beneficiaries with MS.
Main Methods:
- Retrospective analysis of 2011-2014 national Medicare data.
- Monthly DMT adherence defined as proportion of days covered ≥0.80.
- Generalized estimating equation logistic regressions used to identify adherence factors.
Main Results:
- Over 90% of MS patients on Medicare were eligible due to disability; ~75% received low-income subsidies.
- A consistent downward trend in DMT adherence was observed over time.
- Adherence significantly dropped from December to January annually (e.g., 76% to 65% in 1-year sample).
- Low income, disability status, and high out-of-pocket costs were associated with poorer DMT adherence.
Conclusions:
- This study offers critical insights into DMT adherence patterns in Medicare patients with MS.
- Findings underscore the need for targeted interventions and policies to address adherence barriers in this vulnerable population.
Related Concept Videos
01:29Therapeutic Drug Monitoring: Affecting Factors
01:28Drug Therapy
Antianxiety Medications
01:25Factors Influencing Drug Absorption: Disease States and Pharmacology
Substances such as alcohol and specific drugs, including antineoplastics, can also negatively impact drug absorption. For instance,...
01:29Factors Affecting Protein-Drug Binding: Patient-Related Factors
Age stands as a key determinant in protein-drug binding. Neonates, characterized by low albumin content, experience heightened concentrations of unbound drugs such as phenytoin and...
01:22Bioavailability: Influencing Factors
01:15Drug Dosing: Geriatric Patients