Based on the physicians' assessment, the median utility values (and the inter-quartile ranges) for the 4 scenarios associated with metastatic prostate carcinoma were:
state (a) 0.92 (0.88, 0.96);
state (b) 0.84 (0.75, 0.88);
state (c) 0.83 (0.67, 0.88); and
state (d) 0.42, (0.25, 0.59).
The assumptions made regarding the three health states (response with therapy and/or stable state; progression, and death) after the initial 3 months of the start of the disease were as follows:
(1) the survival after progression was the same, independent of flutamide;
(2) the same probability of progression from response or stable disease was assigned;
(3) it was assumed that 95% of untreated patients with severe and minimal disease would die in 7 and 10 year period, respectively;
(4) orchiectomy and LhRH analogs were assumed to be equally effective;
(5) it was assumed that gastrointestinal toxicity would occur in 15% of patients undergoing flutamide therapy within 3 months of starting the therapy.