Modelling the cost effectiveness of interferon beta and glatiramer acetate in the management of multiple sclerosisCommentary: Evaluating disease modifying treatments in multiple sclerosisBMJ 2003; 326 doi: https://doi.org/10.1136/bmj.326.7388.522 (Published 08 March 2003) Cite this as: BMJ 2003;326:522
All rapid responses
ECONOMIC APPROPRIATENESS OF THE EXPENDITURE FOR BETA-INTERFERON IN MULTIPLE SCLEROSIS: ANALYSIS OF NATIONAL PRESCRIPTION DATA IN ITALY
The article by Chilcott et al. (1)
discusses the use of beta-interferon in patients
with multiple sclerosis (MS) and addresses the issue of the high cost of this
In Italy, beta-interferon has been widely prescribed to patients with MS. To interpret
the data of national expenditure (EXPEND) for a given drug class (or for single
pharmacological agent), an innovative method has recently been proposed that
assigns an index of “economic
appropriateness” to the treatment(s) under
examination (2-7). This index is based on the comparison between the health
theoretically expected from EXPEND according to current cost effectiveness
(expected health gain, EHG) and the amount of health that is gained in the
(real health gain, RHG). The value of RHG is estimated using both
and evidence-based information.
In this rapid response, we apply this analysis to the use of beta-interferon in
indications: relapsing-remitting disease and progressive disease). In 2003, a
33.6 million Euros have been spent on beta-interferon in Italy (personal
Bruzzone M and Puca E, Italian Ministry of Health, January 2004). To interpret
this value of
EXPEND, our analysis proceeds as shown in Table 1. Using the benchmark of Euros
per life year gained (or QALY gained), our results indicate that the EHG is
3,360 years, while
the RHG is only 147 years; hence, these findings suggest that the “real” amount
generated by beta-interferon in MS is much less than the amount that would be
using the above mentioned benchmark (RHG/EHG=0.042). Even when the benchmark of
50,000 Euros per life year gained is considered, the two values of EHG and RHG
unfavourable ratio (RHG/EHG=0.22).
The analysis shown in Table 1 has been repeated using different assumptions
duration of treatment (either 6 years or 9 years, with the benchmark of 10,000
life year gained), but the results have remained virtually the same (RHG/EHG=
0.015, respectively). A key factor influencing our analysis is the low value of
quality-adjusted survival gain (0.162 QALYs per patient) attributed to
to Kobelt et al (8). However, this value is in keeping with those published in
the BMJ by
Chilcott et al (1) and by Forbes et al. (9).
There are several limitations in
this simplified ranking approach (2). Anyhow, this method
can be a starting point to improve our interpretation of national prescription
data and, in
particular, can be helpful to identify treatments characterised by a poor
ratio. In the case of interferon given to MS patients, another factor of
uncertainty is the
high rate of treatment discontinuations over time (10), which further
assessment of this difficult therapeutic and economic problem.
Chilcott J, McCabe C, Tappenden P, O'Hagan A, Cooper NJ, Abrams K , Claxton K,
and Miller DH. Modelling the cost
effectiveness of interferon beta and glatiramer acetate in the management of multiple sclerosis. BMJ, Mar 2003; 326: 522.
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TABLE 1. FORMULAS ON
EHG (years or QALYs)* =
Analysis on beta-interferon:
*This calculation can
The publication of Chilcott et al’s paper describing their model for
assessing the cost effectiveness of beta-interferon and glatiramer for
patients with multiple sclerosis (MS) was timely in view of the recent
debate in this journal about the government’s MS risk sharing scheme
[1,2,3]. It makes clear the fact that the cost effectiveness estimates
are highly dependent on the model’s assumptions, and that most of these
are very uncertain. The size and duration of any treatment effect on
disease progression are critically important, yet unknown, emphasising the
need for these to be established in an independent, long-term, randomised
controlled trial. It would be interesting to see how the results of the
model are affected by varying the estimates of treatment effect that are
used in the model as described, since the existence of various biases
[2,4] make it highly likely that these are overestimates.
Cathie Sudlow, Carl Counsell
1. Chilcott J, McCabe C, Tappenden P, O’Hagan A, Cooper NJ, Abrams K,
et al. Modelling the cost effectiveness of interferon beta and glatiramer
acetate in the management of multiple sclerosis. BMJ 2003; 326: 522-525.
2. Sudlow CLM, Counsell CE. Problems with UK government’s risk sharing
scheme for assessing drugs for multiple sclerosis. BMJ 2003; 326: 388-92.
4. Filippini G, Munari L, Incorvaia B, Ebers GC, Polman C, D'Amico R, Rice
GPA. Interferons in relapsing remitting multiple sclerosis: a systematic
review. Lancet 2003;361:545-552.
Competing interests: No competing interests