Donepezil, rivastigmine, galantamine and memantine for ...

patients are seen to discontinue galantamine
treatment (e.g. owing to non-compliance), they are
assumed to have changes in cognition and
psychotic symptoms equivalent to those who had
never received galantamine treatment. Ward and
colleagues report analyses for mild-to-moderate
AD, and two subgroups of patients: those with
moderate disease only (baseline MMSE < 18), and
those responding to treatment (maintained or
improved ADAS-cog over 6 months).
Ward and colleagues report that treatment with
galantamine at a 16-mg dose resulted in an
estimated 12% reduction in the time patients
required FTC, delaying the need for FTC by
2.5 months. At the 24-mg dose the estimated
reduction in time patients required FTC was 15%,
with a delay in the need for FTC of 3.02 months.
The Ward and colleagues model assumes no
survival advantage from galantamine, but
considers health-related QoL. Using health state
utility data from Neumann and colleagues, 110 the
authors apply utilities of 0.60 and 0.34,
respectively, for the health states defined as pre-
FTC and FTC [see discussion of Neumann and
colleagues in the section ‘Health state
utilities/values for AD’ (p. 115)]. Over 10 years the
authors estimate a mean gain of 0.06 QALY (this
finding is not presented by treatment regimen, i.e.
16 or 24 mg). See the discussion of the study by
Neumann and colleagues in the section referred to
above.
Studies by Getsios and colleagues, 95 Garfield and
colleagues, 96 and Caro and colleagues 97 define
their baseline cohort according to trial
participants in trials reported by Raskind and
colleagues 61 and Wilcock and colleagues. 64
Migliaccio-Walle and colleagues 98 define their
patient cohort using combined trial data from
Raskind and colleagues and Tariot and
colleagues. 63 Study methods are reported in
Appendix 13 and findings for these non-UK
studies, with further detail in Appendix 14.
Estimation of costs within economic
evaluations (galantamine)
In line with the AHEAD model format, costeffectiveness
studies assign costs to the health
states for pre-FTC and FTC. Studies estimate the
monthly cost associated with pre-FTC and with
FTC by location, that is, community or
institutional setting. As the AHEAD model
simulates disease progression over time, patients
move from the pre-FTC health state, which is
relatively inexpensive, to the more resourceintensive
health state of FTC. The cost associated
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Health Technology Assessment 2006; Vol. 10: No. 1
with FTC is calculated as a composite cost, with
proportions assigned according to the location of
care (e.g. community or institution). In the
estimation of health state costs, studies use various
country-specific data sources for resource use and
unit costs.
Ward and colleagues 99 in their UK CEA use data
from two UK national surveys (conducted by
OPCS during 1985 and 1986), 134 to estimate the
resource used by cognitively impaired patients
residing in the community or an institutional
setting. Detail on the specific resources used and
subsequent cost analysis is not provided (other
than in one illustrative figure for community care
costs). The authors estimate the cost of providing
FTC to patients in the community at £433 per
month and in an institutional setting £1878 per
month. The estimated monthly costs at lower
levels of dependency (pre-FTC) are £238 per
patient.
From the two UK national surveys Ward and
colleagues assume that 48% of cognitively
impaired patients requiring FTC are living in an
institutional care setting. Although the authors
recognise that the composition of institutional care
has changed considerably since the mid-1980s,
they believe that the proportion of persons in
institutional care as a whole had remained
constant at 48% (no justification provided). For
those persons assumed to be in residential care,
42% were assumed to be in private nursing homes,
37% in private residential care for the elderly, 11%
in local authority care, 8% in voluntary residential
care and 2% in hospital. These estimates were
based on data taken from published sources on
persons with dementia.
Ward and colleagues report the expected 10-year
cumulative costs per patient were £28,134 for the
non-galantamine treatment cohort, £28,615 for
the galantamine 16 mg/day cohort (increase of
1.7% over no treatment) and £28,806 for the
galantamine 24 mg/day cohort (increase of 2.4%
over no treatment). Treatment with galantamine
increased annual costs for the first 3 years, with
costs in subsequent years partially offset by
delaying the need for FTC and with 80% of the
treatment cost (galantamine cost) expected to be
offset over 10 years.
For subgroup analyses, Ward and colleagues
predict small cost savings over time of £228 in
moderate AD (16 mg/day galantamine) and more
substantial savings at £1372 (16 mg/day
galantamine) in the subset of patients who
99