Related Experiment Video
Updated: Jun 12, 2026
The Multiple Sclerosis Performance Test (MSPT): An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
Cost sharing, benefit design, and adherence: the case of multiple sclerosis
Avi Dor1, Maureen J Lage, Marcy L Tarrants
1George Washington University, Washington, DC, USA.
Purpose:
The authors focus on understanding the relationship between costs and cost sharing on medication adherence for individuals who initiated a disease-modifying therapy (DMT) for the treatment of multiple sclerosis (MS). DMTs reduce the risk of relapse and are an essential component of MS treatment. Furthermore, the authors compare monthly payment levels for copayments versus coinsurance and estimate the effects on adherence.
Methods:
Using the MarketScan Commercial Claims and Encounters database evidence from July 1 2005 to March 31 2008, the authors employ a multivariate two-stage least-squares model (2SLS) to examine the impact of copayments or coinsurance on the medication possession ratio (MPR).
Findings:
Descriptive results show that the mean out-of-pocket (OOP) costs of DMT per month were higher for patients with coinsurance than for patients with copayments. For the cohort of patients with copayment there was little difference in monthly copayments across adherence thresholds. Regression analysis shows that an increase in cost sharing reduces adherence overall, but this effect was small and insignificant in the copayment cohort. In contrast, in the coinsurance cohort increased cost sharing was significantly associated with decreased adherence to DMT medication; with a 10% increase in cost sharing leading to an 8.6% decline in adherence.
Implications:
Employers increasingly rely on coinsurance, despite evidence that reliance on coinsurance results in lower adherence. Our research findings suggest that coinsurance appears to be a greater obstacle to compliance, confirming predictions found in the theoretical literature.
Originality:
This research converted counts of injectable treatments into a continuous adherence measure. Previous literature on cost sharing did not examine MS.
Related Concept Videos
01:15Methods of Documentation VI: Case Management Model
For example, a patient with a chronic illness...
01:19Multiple Sclerosis l: Introduction
01:26Methods Of Healthcare Delivery System
Managed Care System:
The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is limited...
01:29Documentation in Long-Term and Home Healthcare Setting
Long-Term Care Facilities
01:16Crossover Experiments
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...