Dissertation Title："Patient Preferences and Economic Considerations in Treatment Decisions for Multiple Sclerosis"

This thesis explores the role of patient preferences in treatment decisions and in the cost-effectiveness of three treatments for patients with multiple sclerosis (MS).

The first chapter reports the results of a survey conducted to measure utilities for six health states and three treatment states in multiple sclerosis. Patients assign high utilities to milder MS health states and disutility is associated with the treatment health states. Mean utilities for the treatment health states were lower than those for the milder MS health states. These results provide support for a hypothesis that a patient’s decision to discontinue treatment is rational.

The second chapter examines the role of risk attitude and treatment choice in patients with multiple sclerosis. Patients’ risk profiles regarding health and money were assessed using standard-gamble questions. The main finding of this chapter is that risk attitude is related to treatment choice for patients with MS. As patients become more risk seeking, they are more likely to forgo treatment. Treatment discontinuation, however, is not associated with risk attitude. Patients who discontinue do so because they have experienced moderate or severe side effects, regardless of risk preference. An additional finding of this paper is that risk attitude varies across domains. While respondents were, on average, risk averse with respect to money, they were risk neutral on health. Therefore, risk attitude regarding money may not be an appropriate proxy for risk attitude regarding health.

The third chapter evaluates the cost-effectiveness of interferon beta-1a, interferon beta-1b, and glatiramer acetate in patients with multiple sclerosis. A computer simulation to model the effects and costs of treatments in multiple sclerosis was developed. Cost-effectiveness ratios for all three treatments are unfavorable under most assumptions, unless the cost of the drug is substantially reduced. All three treatment strategies are strongly dominated in the base case analysis; for treatment duration of five years or less, benefits are not large enough to overcome disutility associated with the treatments. Using alternative assumptions, cost-effectiveness ratios are still greater than $1,000,000/QALY in most cases. Under favorable assumptions, cost-effectiveness ratios may be as low as $460,000/QALY for IFNB-1a.