Donepezil, rivastigmine, galantamine and memantine for ...

to stochastic data input, to address uncertainty in
parameter inputs (as detailed in Table 71). Table 74
reports selected one-way and multi-way sensitivity
analysis to address uncertainty in other parameter
inputs, and in structural/methodological
uncertainty.
Health Technology Assessment 2006; Vol. 10: No. 1
TABLE 74 Sensitivity analysis, against probabilistic results, selected one-way and multiple sensitivity analysis using the above model
with parameter/input variations
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Cost per QALY (£)
Results of sensitivity/inputs Donepezil Rivastigmine Galantamine
10 mg 6–12 mg 24 mg
Base case 96,797 70,438 81,910
No discounting 97,751 73,692 82,246
Discount rates at 3.5% for future costs and outcomes 104,184 76,492 84,651
Assume all institutional costs met by NHS and PSS 87,096 62,269 71,971
Assume 85% of institutional costs met by NHS and PSS 94,847 65,851 76,843
Assume presence of EPS and psychotic symptoms in 20% of cohort 85,973 63,262 74,994
Assume a benefit of treatment on psychotic symptoms: with 20%
reduction in the proportion of patients showing presence
of symptoms:
Base case (10% with symptoms) 94,839 68,117 78,145
20% with psychotic symptoms 84,389 58,652 71,722
75% with psychotic symptoms 56,039 37,996 48,816
AD duration (mean):
2.66 years (SD 1 year) 103,106 76,288 87,056
Assumptions on location of FTC:
20% community, 80% institution 84,495 57,424 71,513
60% community, 40% institution 95,217 74,414 84,632
Assume no entry cost (drug/monitoring) for treatment cohort 70,886 53,780 63,103
Assume all costs met by NHS and 80% of FTC patients in 69,428 40,061 50,868
an institutional setting
Assume additional healthcare costs for institutional patients at
(per year):
£1000 105,069 73,780 86,549
£10,000 92,140 62,923 76,208
Assume costs for pre-FTC are (per month/cycle):
£150 (SD £75) 92,287 60,376 75,020
£600 (SD £300) 109,446 82,479 95,595
Assumptions on health state utilities:
Pre-FTC 0.75, FTC 0.20 (diff. 0.55) 45,275 33,552 38,456
Pre-FTC 0.50, FTC 0.20 (diff. 0.30) 84,576 59,975 69,919
Pre-FTC 0.50, FTC 0.34 (diff. 0.16) 161,360 111,418 136,980
Effectiveness estimate:
+1 point on base-case ADAS-cog 66,505 49,065 57,119
–1 point on base-case ADAS-cog 150,214 120,915 122,571
Mortality at (per year):
0% 76,365 54,103 61,477
8% – all patients 91,113 65,843 77,498
15.4% – all patients 108,125 76,662 91,603
Assume all costs met by NHS, 80% of FTC patients in institution, 62,564 35,885 44,822
and mortality annual rate of 8% (all patients)
Assume additional (to base case) monitoring cost:
+1 additional outpatient visit per year 103,411 81,080 87,753
+1 outpatient appointment, and an additional 2 GP visits per year a 110,898 83,541 99,162
a GP visit assumed to cost £26 (assume SD of £13); PSSRU.
Deterministic analyses are also presented, and
sensitivity analysis for deterministic analysis
reported in Appendix 18, with relative differences
showing a similar sensitivity of results to those
presented below.
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