Long-term cost-effectiveness model of interferon beta-1b in the early treatment of multiple sclerosis in the United States.
BACKGROUND
Multiple sclerosis (MS) is a potentially debilitating autoimmune disease that affects the brain and spinal cord. Disease-modifying therapies have been shown to slow disease progression but were not believed to prolong the survival of patients with MS. The recent 21-Year Long-Term Follow-Up (21Y-LTF) study found a significant survival advantage for patients receiving early treatment with interferon beta (IFNβ)-1b compared with placebo (no early treatment).


OBJECTIVE
The aim of this study was to conduct cost-effectiveness analyses estimating the long-term benefit of early treatment with IFNβ-1b among MS patients from a US societal perspective.


METHODS
A Markov model was developed to simulate the experience of patients with MS from the 21Y-LTF study over a lifetime. Patients were randomized to receive either IFNβ-1b or placebo for up to 5 years and then receive a variety of MS treatments (including no treatment) thereafter. Survival data reported from the 21Y-LTF study were incorporated into the model. The model assumes that patients' MS was managed in similar ways for both groups during the uncontrolled phase of the 21Y-LTF study (ie, survival difference between the 2 groups is the result of early use of IFNβ-1b). Health outcomes were life-years and quality-adjusted life-years (QALYs). Costs included treatments, direct disease management, informal care, and lost productivities and were reported in 2011 US dollars.


RESULTS
In the modeled placebo group, the median age at death was predicted to be 63.7 years, and the median survival time from disease onset was 36.7 years. Early treatment with IFNβ-1b reduced the lost health benefits by 2.8 life-years and 1.9 QALYs, respectively, after discounting. Total discounted cost for IFNβ-1b-treated patients was $86,223 higher than that of patients receiving placebo. The incremental cost-effectiveness ratio was $46,357 per QALY gained and $30,967 per life-year gained. Sensitivity analyses indicate the robustness of the model's results.


CONCLUSIONS
Treatment with IFNβ-1b during the earlier disease phase of patients with MS significantly increased patient life-years and QALYs. IFNβ-1b is likely to be a cost-effective intervention for MS.
United BioSource Corporation, Bethesda, Maryland 20814, USA. feng.pan@unitedbiosource.com
Feng
F
Pan
Jo Wern
JW
Goh
Gary
G
Cutter
Wayne
W
Su
Dirk
D
Pleimes
Cheng
C
Wang
D000276:Adjuvants, Immunologic / Q000191:economics / Q000627:therapeutic use*; D000368:Aged; D003362:Cost-Benefit Analysis; D018450:Disease Progression; D016527:Drug Costs; D005500:Follow-Up Studies; D006801:Humans; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000191:economics / Q000627:therapeutic use*; D008390:Markov Chains; D008875:Middle Aged; D018803:Models, Economic; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000191:economics; D019057:Quality-Adjusted Life Years; D015996:Survival Rate; D013997:Time Factors; D014481:United States
D000276:Adjuvants, Immunologic; D000068576:Interferon beta-1b; D016899:Interferon-beta