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

TABLE 43 Utility values including/excluding adverse events
These utility values were used to estimate the
mean (and standard error) for the utility
decrement associated with the different
chemotherapies (reported in Table 44). These
adjustments were applied to a single cycle of the
model and hence we assumed that the duration of
the adverse event (and hence the decrement)
lasted for a maximum of 1 month. Gamma
distributions were assigned to these data for the
purposes of the probabilistic analysis, using
method of moments.
In the absence of utility decrements for the
complete range of possible strategies, the
following assumptions were applied. The
decrement reported for docetaxel was applied to
the two D + P strategies (3-weekly and weekly).
For the docetaxel and estramustine strategies
(D + E and D + E + P 35 and 70), the decrement
applied was taken as the maximum estimated for
docetaxel and estramustine. The decrement
reported for mitoxantrone was applied to both of
the mitoxantrone-based comparators (M + P and
M + P + C). Finally, in the absence of data for the
Health Technology Assessment 2007; Vol. 11: No. 2
Health State n Mean SE
Moderate disease 27 0.7319 0.0438
Moderate disease + docetaxel AE 27 0.5972 0.0519
Moderate disease + mitoxantrone AE 27 0.6643 0.0455
Moderate disease + estramustine AE 27 0.6222 0.0482
AE, adverse events.
TABLE 44 Utility decrements applied in the sensitivity analysis
Intervention Mean SE Distribution
Docetaxel 0.1347 0.0679 Gamma
Mitoxantrone 0.0676 0.0632 Gamma
Estramustine 0.1097 0.0651 Gamma
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adverse event profile reported for
prednisone/prednisolone, the lowest decrement
across the three different interventions was
applied. Although this approach resulted in
similar decrements applied to more than one
strategy, the total impact on the QALY calculations
was specific for each intervention, since the
probability of experiencing grade 3/4 adverse
events was separately estimated for each
intervention in the Bayesian meta-analysis.
Tables 45 and 46 report the results of the sensitivity
analysis including the adverse events. The results
demonstrate that the ICER appears robust to the
inclusion of adverse events. The ICER of D + P
(3-weekly) in comparison with M + P increases
marginally to £33,298 per QALY when adverse
events are included (compared with £32,706 per
QALY in the main analyses).
Variation in the health state descriptive
system
Three separate health states were used to describe
the progression of advanced disease in HRPC in
order to reflect the QoL of early, moderate and
late disease. These health state descriptions were
devised using data reported using FACT-P. For the
purposes of the cost-effectiveness analysis, these
estimates were combined to reflect a single utility
value. The utility values for each state (including
the combined estimate) are reported in Table 47.
The valuations provided for each of the states, and
the combined estimate, were higher than the
TABLE 45 Analysis 1 – estimates of mean lifetime costs and QALYs for D + P (3-weekly), M + P and P, including adjustment for
adverse events
Intervention Cost (£) LYG QALY ICER (£) Probability cost-effective (%)
£20,000 £30,000 £40,000
P 11,242 1.51 0.80103 Dominated 41 35 28
M + P 10,801 1.51 0.79917 – 38 29 20
D + P (3-weekly) 15,859 1.80 0.95107 33,298 21 36 51
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