Cost-effectiveness of disease-modifying therapy for multiple sclerosis: a population-based study

Abstract

Objective: To evaluate the cost-effectiveness of disease-modifying therapies (DMTs) in the United States compared to basic supportive therapy without DMT for patients with relapsing multiple sclerosis (MS).

Methods: Using data from a longitudinal MS survey, we generated 10-year disease progression paths for an MS cohort. We used first-order annual Markov models to estimate transitional probabilities. Costs associated with losses of employment were obtained from the Bureau of Labor Statistics. Medical costs were estimated using the Centers for Medicare and Medicaid Services reimbursement rates and other sources. Outcomes were measured as gains in quality-adjusted life-years (QALY) and relapse-free years. Monte Carlo simulations, resampling methods, and sensitivity analyses were conducted to evaluate model uncertainty.

Results: Using DMT for 10 years resulted in modest health gains for all DMTs compared to treatment without DMT (0.082 QALY or <1 quality-adjusted month gain for glatiramer acetate, and 0.126-0.192 QALY gain for interferons). The cost-effectiveness of all DMTs far exceeded $800,000/QALY. Reducing the cost of DMTs had by far the greatest impact on the cost-effectiveness of these treatments (e.g., cost reduction by 67% would improve the probability of Avonex being cost-effective at $164,000/QALY to 50%). Compared to treating patients with all levels of disease, starting DMT earlier was associated with a lower (more favorable) incremental cost-effectiveness ratio compared to initiating treatment at any disease state.

Conclusion: Use of DMT in MS results in health gains that come at a very high cost.

Figure 1. Overview of the simulation model

We draw and redraw multiple samples of patients with multiple sclerosis (MS) from the Slifka survey cohort to estimate health care utilization, health utility, and disease progression probabilities. Using Monte Carlo simulations, we modeled 10-year MS progression paths for treatment and untreated individuals. ICER = incremental cost-effectiveness ratio.

Figure 2. Cost-effectiveness acceptability curves: Current drug prices (A) and 67% price reduction (B)

We plotted probability of being cost-effective (vertical axes) vs cost-effectiveness threshold value (willingness to pay) (horizontal axes) for the cost of 1 year in perfect health ($/quality-adjusted life-year) using current disease-modifying therapy medication prices (A) as well as reduced prices (B).