Donepezil, rivastigmine, galantamine and memantine for ...

TABLE 71 Estimate of annual NHS and PSS cost for persons in health state FTC
proportion of the drug treatment and usual care
cohorts in health states pre-FTC and FTC over
time.
Assessment of uncertainty in the SHTAC
analysis
Sensitivity analysis was undertaken to address
uncertainty in the CEA. Methodological and
structural uncertainty is considered by addressing
assumptions on proportions of institutional costs
met by the NHS and PSS, proportions of patients
in FTC by location and assumptions on
monitoring.
Parameter uncertainty has been considered, where
possible, as part of the probabilistic modelling
process, with distributions around point estimates
allowing variation within the main analysis (e.g.
age, ADAS-cog score, AD duration, effectiveness,
monitoring costs, costs for pre-FTC and FTC and
health state utilities), but this has not been
possible in all instances. Therefore, where
parameter values have not been varied in a
probabilistic manner, sensitivity analysis has been
undertaken on these parameters by re-running
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Health Technology Assessment 2006; Vol. 10: No. 1
FTC in FTC in institutional setting Total expected
community annual cost for FTC
Institutional costs Other NHS/PSS
costs
Annual cost (£) 5,196 18,471 4,874
Proportion publicly funded (%) All 70 All
Proportion of FTC patients 52 48 48
by setting (%)
Cost (£) 2,702 6,206 2,339 11,247
Source: FTC in community and proportion of FTC in community from Ward et al., 99 institutional living costs and proportion
publicly funded from Netten et al., 130 other NHS/PSS costs for institutionalised patients from Ward et al. 99 All costs uprated
to 2002–03 costs (Hospital and Community Health Services index).
TABLE 72 SHTAC cost-effectiveness results (donepezil, rivastigmine, galantamine)
Product Difference/reduction in time spent Incremental Incremental Cost per
in FTC (months), over 5 years cost (£) QALY QALY (£)
(non-discounted)
Deterministic results
Donepezil 10 mg 1.59 (1.71) 2,894.81 0.036 80,941
Rivastigmine 6–12 mg 1.63 (1.75) 2,121.18 0.037 57,985
Galantamine 24 mg 1.73 (1.86) 2,647.58 0.039 68,042
Probabilistic results
Donepezil 10 mg 1.42 (1.53) 3,084.83 0.032 96,757
Rivastigmine 6–12 mg 1.43 (1.54) 2,302.75 0.033 70,438
Galantamine 24 mg 1.54 (1.66) 2,862.55 0.035 81,910
probabilistic analysis with different point estimates
(e.g. mortality rates, presence of EPS and
psychotic symptoms). Further analyses have been
run for variations in parameter variations for
health state utilities and effectiveness estimates
(assuming similar distributions).
SHTAC cost-effectiveness results
(donepezil, rivastigmine, galantamine)
The mean survival time in the SHTAC model is
45 months (41.8 discounted months) and the
mean time on drug treatment is 27.8 months
(across all three products). Table 72 presents
ICERs, cost per QALY, for drug treatment plus
usual care versus usual care alone. Results are
presented for deterministic analysis and
probabilistic analysis. For deterministic analysis
the estimated cost per QALY ranges from £57,985
(rivastigmine 6–12 mg) to £80,941 (donepezil
10 mg). Findings using probabilistic analysis show
a higher cost per QALY, ranging from £70,438
(rivastigmine 6–12 mg) to £96,757 (donepezil
10 mg). The incremental QALY gains over the
5-year period are small and the cost per QALY
estimate is sensitive to small changes in the
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