Donepezil, rivastigmine, galantamine and memantine for ...

SHTAC analysis of cost-effectiveness of
donepezil, rivastigmine and
galantamine using the industry models
submitted to NICE
Donepezil – SHTAC adjustments to industry
model
The industry model estimating the costeffectiveness
of donepezil uses health states
according to disease severity (MMSE categories),
and SHTAC have estimated alternative cost inputs
for these health states using their cost estimates
for pre-FTC and FTC for AD (see above). We use
our estimate of pre-FTC for the minimal and mild
health states, with moderate AD comprising 50%
of patients at pre-FTC, 38.5% at a cost for FTC in
the community and 11.5% assumed to be in a
health state of FTC in an institution (this later
estimate of FTC institution is based on data from
Fenn and Gray 91 ). For the severe AD health state
we assume all patients are in the health state of
FTC, with 80% in an institution and 20%
receiving FTC in the community. These
alternative cost estimates are illustrative of an AD
treatment profile, and are provided to consider
alternative estimates from the industry model. In
addition to the general costs for care of AD, we
also add to the drug treatment cohort the cost per
year for donepezil 10 mg (£1248) and a
monitoring cost (£206, as discussed in SHTAC
analysis above). Table 75 details these alternative
cost estimates.
These alterations do not mean that SHTAC have
rewired/reworked the model in any way, or that
SHTAC accepts the method used in the model.
Alternative results are presented here for
illustrative purposes only.
Applying the above cost profile to the industry
model, keeping all else as presented in the
industry model, results in an estimate of £12,975,
using deterministic analysis, effectiveness scenario
TABLE 75 SHTAC cost inputs to donepezil model
© Queen’s Printer and Controller of HMSO 2006. All rights reserved.
Health Technology Assessment 2006; Vol. 10: No. 1
C and half-cycle correction assumptions (industry
base case was £7449). Where we also adjust the
model to incorporate an increased mortality risk
(11% per year), the estimate increases to £13,509.
Were these estimates to be based on probabilistic
analysis we expect the cost per year in a nonsevere
AD health state to be well above £15,000
and any subsequent cost per QALY estimate to be
in excess of £50,000. This potentially large cost
per year of non-severe AD is also based on what
we regard as optimistic effectiveness assumptions
(using the transit probabilities from one clinical
trial), and subsequent alterations to these
effectiveness assumptions would also, we believe,
have a major impact on the cost-effectiveness
results, pushing the cost per year in a non-severe
health state to a higher estimate.
Rivastigmine – SHTAC adjustments to industry
model
Where SHTAC have used the industry model
(deterministic analysis) with alternative inputs to
cost data and the utility methods, specified below,
we see a cost per QALY of £45,925. These
alterations do not mean that SHTAC have
rewired/reworked the model in any way, or that
SHTAC accepts the method used in the model;
alternative results are presented here for
illustrative purposes only.
Adjustments made by SHTAC to industry basecase
model inputs:
1. Institutionalisation cost set at £18,471 per year,
with 70% of this falling on the NHS and PSS
budget (£12,929) (base case at £16,380 per
year).
2. Home care costs set at £3937 per year (an
increase) (base case at £3231).
3. Monitoring cost (additional for rivastigmine
treatment) set at £208 per year (a reduction on
the base-case cost set at £468 per year).
AD severity Industry model SHTAC estimate; components of total SHTAC SHTAC
group cost data (£) care costs (£) total care total care
cost cost
Placebo Treatment Pre-FTC FTC – FTC – (placebo) (treatment)
(including care community institution (£) (£)
donepezil) care care
Minimal 9,515 10,735 100% × 3,973 0% × 5,196 0% × 17,803 3,973 5,427
Mild 13,327 14,548 100% × 3,973 0% × 5,196 0% × 17,803 3,973 5,427
Moderate 17,949 19,170 50% × 3,973 38.5% × 5,196 11.5% × 17,803 6,034.39 7,488
Severe 25,488 25,488 0% × 3,973 20% × 5,196 80% × 17,803 15,282.16 15,282
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