Docetaxel with prednisone or prednisolone for the treatment of ...

72
Economic model
Population EVPI (£ million)
20
18
16
14
12
10
8
6
4
2
0
0 5000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000
Maximum acceptable ratio () (£)
FIGURE 10 Population EVPI for the decision between D+P (3-weekly), M + P, P, D + P (weekly), D + E, D + E + P (70), D + E +
P (35) and M + P + C
strategy identified as optimal is implemented
universally). The expected value of perfect
implementation (EVPIm) is simply the difference
in the costs and outcomes (net benefit) between
the optimal strategy implemented perfectly and as
currently.
As with value of information analysis, EVPIm
can be expressed for the total population who
stand to benefit over the expected lifetime of
the programme/technology. The population
EVPIm gives a measure of the maximum return
to strategies to change implementation and
provides a necessary condition for determining
whether such strategies are potentially
worthwhile. The overall value of implementation
for a population is determined by applying
the individual EVPIm estimate to the number of
people that would be affected by implementation
over the anticipated lifetime of the
technology:
T I t
EVPIm* ∑ –––––––
t = 1(1 + r) t
where I = incidence in period, t = period,
T = total number of periods for which
information from research would be useful and r
= discount rate.
The population information for the value of
implementation analysis was the same as was used
for the value of information analysis (2748
patients per annum for 1.5 years). A recent audit
undertaken by the British Prostate Group, British
Uro-Oncology Group and British Association of
Urological Surgeons identified the use of
chemotherapy regimens for HRPC in 33 centres
nationwide. The use of D + P (3 weekly), M + P
and P were identified as 33, 38 and 18%,
respectively. We assumed that the remaining 11%
was allocated to the remaining five treatments
such that D + P (weekly) was used 5% of the time,
D + E was used 1% of the time, M + P + C was
used 2.8% of the time and D + E + P (70) and
D + E + P (35) were each used 0.9% of the
time.
Figure 11 illustrates the EVPIm, the EVPI and the
expected value of ‘perfection’ for the population
(as described above) based on Analysis 2. As
detailed above, the EVPI curve increases over the
full range of values for the maximum acceptable
ratio, with a local maximum occurring at the value
that corresponds to the ICER (£32,706). The