However, unlike the CT negative results we see the ICER for CT positive patients
increase as the rate of upstaging is increased. This is because slightly more upstaging occurs in
the PET strategy than the CWU strategy with 0.525 patients being upstaged compared to 0.43
due to false negatives in PET proceeding straight to surgery without a mediastinoscopy.
Therefore, we see the PET versus the CWU strategy becoming less cost effective with the
ICER increasing to $A 55,827 when the rate of upstaging is increased and falling to $A 50,144
when the rate of upstaging is decreased. These results may radically change if QALY
assumptions are introduced.
Radiotherapy and chemotherapy costs
There was much uncertainty about the chemotherapy and radiotherapy costs in the
model as there is no certain Australia data on costs of these treatments in NSCLC. Therefore, a
two way sensitivity analyses was carried out to take account of this uncertainty and can be seen
in table 13 for CT negative patients and
Table 13: Two way sensitivity analysis of the cost of chemotherapy and radiotherapy in
CT negative patients
Chemotherapy Costs | ||||||||
Radiotherapy Costs |
4000 |
6000 |
8000 |
9,784 |
10000 |
12000 |
14000 | |
6000 |
696.1 |
1373.1 |
2050.1 |
2653.9 |
2727.0 |
3404.0 |
4081.0 | |
8000 |
3707.2 |
4384.2 |
5061.2 |
5665.0 |
5738.1 |
6415.1 |
7092.1 | |
10000 |
6718.3 |
7395.3 |
8072.3 |
8676.1 |
8749.2 |
9426.2 |
10103.2 | |
12000 |
9729.4 |
10406.4 |
11083.4 |
11687.2 |
11760.3 |
12437.3 |
13114.3 | |
13922 |
12623.1 ________4_ |
13300.1 |
13977.0 |
14580.9 ________5_ |
14654.0 |
15331.0 |
16008.0 | |
14000 |
12740.5 |
13417.5 |
14094.5 |
14698.3 |
14771.4 |
15448.4 |
16125.4 | |
16000 |
15751.6 |
16428.6 |
17105.6 |
17709.4 |
17782.6 |
18459.5 |
19136.5 | |
18000 |
18762.7 |
19439.7 |
20116.7 |
20720.5 |
20793.7 |
21470.6 |
22147.6 | |
20000 |
21773.8 |
22450.8 |
23127.8 |
23731.6 |
23804.8 |
24481.7 |
25158.7 |
The results show that in the CT negative patients that as the costs of radiotherapy and
chemotherapy increase the ICERs is also increases. This reflects that PET correctly stages
more patients with N2/3 for joint chemotherapy and radiotherapy and identifies more patients
with M1 disease than the CWU strategy. However, the ICERs for the CT negative patients do
not change greatly considering the large movements in the costs and never become excessively
high.
23