The CT positive patients show that the mean is also very close to the mean in the
original baseline result but not as close as the CT negative results with the a difference of
around $A 816 per QALY cheaper than the PSA result. But the most interesting result is that
the median is so low compared to the median suggesting that there is a substantial amount of
skewness in the results and this could be potentially suggesting that the is a lot of variability in
outcomes and is further evidence to question PET as a cost effective strategy in CT positive
patients.
Table 17: The mean, median and inter quartile range for Ct positive patients in the
simulation
CT |
Incremental Costs |
Incremental |
ICER | |
Mean |
16742.87 ~ |
0.33 ~ |
50854.9 | |
Median |
15499.46 |
0.40 |
27256.2 | |
Inter- |
25 |
5813.80 |
0.20 |
64.8 |
75 |
26654.65 |
0.56 |
62985.8 |
We now turn to look at the cost effectiveness acceptability curve (CEAC) for PET and
CWU in NSCLC for CT negative patients. A CEAC shows the probability that an intervention
is more cost effective than it comparator. The results for CT negative patients show that as the
threshold willingness-to-pay increases the probability that PET is cost effective rises while the
probability that CWU is cost effective decreases. 48 The CEAC shows the decision maker the
probability that they have made the right on wrong decision and, in this case, the decision
maker will make the right decision more than 50% of the time if the willingness to pay is just
over $A 15,000, while if the decision maker is willing to pay $A 50,000 the probability that
they have made the right decision increases to 90%.49
48 Drummond et al, Methods for the Economic Evaluation of Health Care Programmes; Third edition. (Oxford,
O.U.P, 2005), p. 265.
49 Drummond et al, Methods for the Economic Evaluation of Health Care Programmes; Third edition. (Oxford,
O.U.P, 2005), p. 267
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