Long Term Treatment of Multiple Sclerosis with Interferon-?? May Be Cost Effective

Abstract

Multiple sclerosis (MS) is a devastating disease that can occur in early life, progressing to rapid disability and loss of physical, psychosocial and economic functioning, significantly affecting quality of life. The traditional treatment for MS has been symptomatic, treating acute relapses without affecting the underlying disease. The introduction of interferon-beta (IFN beta) has offered significant clinical benefits by reducing the frequency of relapses and slowing disease progression. Although the costs of this treatment are high, the costs to society of caring for a patient disabled by MS are greater, and if IFN beta can delay disease progression in the longer term, the economic impact would be substantial. Previous pharmacoeconomic studies of IFN beta have suggested that benefits can only be achieved at extremely high cost, with reported cost-effectiveness measures of up to 1 million pounds sterling (Pound) per quality-adjusted life year (QALY) [1995 values]. However, these studies have considered only the short term benefits of IFN beta treatment: over 2 to 3 years, the impact of treatment on patients' quality of life is relatively small, and cost-utility analyses that do not consider longer term benefits nor include societal costs may be misleading. The model reported here is based on the hypothesis that the delay in disease progression seen in short term clinical trials is likely to continue if treatment is continued. The model also assumes that the delay in disease progression, which represents a reduction in brain atrophy, will result in lasting clinical benefits even if treatment is stopped. These assumptions are strongly supported by clinical trial data and the treatment hypothesis itself. A delay in disease progression will result in a significant improvement in functioning and quality of life, and if the costs associated with increased disability can be postponed, even long term treatment of MS with IFN beta can be shown to be cost effective. Using resource utilisation costs derived from an economic evaluation of MS in the UK, it was possible to calculate the impact of delaying disease progression in terms of both health service and societal costs. An estimate of mean disease progression in patients with MS treated with IFN beta-1a compared with patients who did not receive disease-modifying agents suggested that significant cost savings would be realised after about 12 years' treatment with IFN beta-1a. The application of utility scores to the disease progression curves also facilitated estimates of cost effectiveness, with cost per QALY values ranging from 27,036 Pounds after 2 years' treatment with IFN beta-1a to 37,845 Pounds after 20 years' treatment (1995 values).

Cost-effectiveness of disease-modifying therapy for multiple sclerosis

“…Our results are consistent with results reported in other studies conducted by independent academic groups, 7,12 but are substantially less favorable than the results of industrysponsored investigations. 8,16,33,34 This is likely due to the funding effect and the conflict of interest bias that may enter into the model design, estimating parameters, and interpretation of CE study results. 35 We also recognize potential sample selection issues.…”

“…Several cost-effectiveness (CE) models of MS DMTs have been developed for different patient populations including those in the United States, [7][8][9][10] Canada, 11 and various European countries. [12][13][14][15][16][17][18] Published studies have produced a range of estimates from over $2 million per quality-adjusted life-year (QALY) to being costsaving. There is, however, a substantial body of literature indicating that evidence from CE models is not easy to transfer from one country to the other and that country-specific evidence is required for each policy decision.…”

Methods for expected value of information analysis in complex health economic models: developments on the health economics of interferon-β and glatiramer acetate for multiple sclerosis

“…Existing analyses have produced a range of cost-effectiveness estimates from in excess of £1 million per QALY gained to cost saving. [30][31][32] Significant flaws in the modelling of natural history, efficacy, discontinuation of therapy, mortality and the treatment of uncertainty mean that none of these estimates can be considered robust. 33 In general, those models which produced very high cost-effectiveness estimates tended to have shorter time horizons (less than 10 years) or assumed that all benefit ceased when the patient stopped therapy.…”

Cost-utility of interferon β 1b in the treatment of patients with active relapsing-remitting or secondary progressive multiple sclerosis

“…Economic evaluations of treatments for multiple sclerosis have focused either on relapsing-remitting or secondary progressive disease.None has addressed specifically the question of how treatments affect disease progression from diagnoses to severe disability; however, in both clinical and economic terms this is one of the key questions.This study therefore created a disease model that includes both relapsing and progressive multiple sclerosis and covers the full range of disease severity.In addition, the issue of covariates influencing the cost per QALY and the uncertainty in the estimates is addressed.The model is based on our earlier approach using a Markov model, where disease progression is measured as functional disability (EDSS), costs and utilities associated with different disability levels, and outcome expressed as QALY.Treatment is based on a subgroup of patients with active disease in two placebo-controlled clinical trials and open-label extensions with interferon-β 1b in relapsing-remitting or secondary progressive multiple sclerosis, and natural history data are used for the extrapolation beyond the trials.Disease progression (transition probabilities) was estimated using a probit model controlling for differences in patient and disease characteristics, and costs and utilities for different disability levels are taken from large population-based observational studies.Results are presented for Sweden and compared to the United Kingdom.When treatment is given for 36 months (adjusted for compliance) and no further Anumber of economic evaluations of treatments in multiple sclerosis (MS) have been published in recent years [1,2,3,4,5,6], driven by the introduction of several new treatments [7,8,9,10,11,12,13].All of these evaluations have focused on one type of the disease, either on relapsing-remitting (RRMS) or secondary progressive disease (SPMS), depending on the clinical trial underlying the analysis. Thus none of these analyses has addressed the question of how treatments affect disease progression from diagnoses to severe disability.…”