Stability of time trade-off utilities for health states associated with the treatment of prostate cancer

Background: Patients diagnosed with localized prostate cancer face several treatment options. Patient preferences for treatment side effects often dominate the decision making process. We proposed to learn more about the nature of patient preferences, or utilities, for these side effects. Methods: Two hundred and fifteen men were consecutively enrolled from three institutions for assessment after prostate needle biopsy. Baseline and 6 month follow-up assessments were done using the University of California, Los Angeles Prostate Cancer Index (UCLA PCI), and a laptop utility assessment application, U-Titer II. Patient utility was assessed for current pelvic functions as well as hypothetical pelvic dysfunctions. We calculated stability of utility scores and correlations between utility scores and UCLA PCI scores. Results: Utility scores for current pelvic functions exhibited a significant ceiling effect. Utility scores for current pelvic functions and hypothetical impaired states were stable after 6 months in patients with negative biopsies. In patients who underwent treatment, utility for current sexual function decreased by 0.13 units (p < 0.00) and utility for current urinary function decreased by 0.09 units (p < 0.01). Utility for hypothetical stress urinary incontinence rose in men with a >25-point drop in UCLA PCI score. Conclusion: Utilities for some current pelvic functions decreased in tandem with UCLA PCI scores in men who experienced >25-point changes in these scores. Utilities for some hypothetical pelvic dysfunctions rose as men began to actually experience functional changes in those areas.