Robust Health Utility Assessment Among Long-term Survivors of Prostate Cancer: Results from the Cancer of the Prostate Strategic Urologic Research Endeavor Registry

Abstract

Background: Valid health utility values are essential for comparative effectiveness analyses. However, subjective utilities in long-term survivors of prostate cancer (PCa) with various oncological and functional outcomes have not been well described. Objective: To quantify utilities in long-term survivors of PCa using the standard gamble method, generally regarded as the approach best grounded in economic theory. Design, setting, and participants: We performed a cross-sectional study nested within a prospective cohort—Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE). Overall, 1884 (59.7%) of 3155 active participants across all disease states returned the questionnaire. Intervention: Various primary treatments for PCa. Outcome measurements and statistical analysis: Utility values for PCa health, sexual function, urinary function, bowel function, and overall health were measured, based on patients’ conditions at the time of the survey. Bias correction methods were employed. Results and limitations: After exclusion of incomplete or disqualified data, 1740 (92.3% of responding) patients were included in the final analysis. The mean age was 73.1 ± 8.2 yr at a median of 9 yr (interquartile range: 6–11) since diagnosis. Mean utilities for PCa health and overall health were 0.934 ± 0.120 and 0.960 ± 0.100, respectively. After bias correction by probability weighting function, utilities were 0.866 ± 0.154 and 0.897 ± 0.142, and by mixed model correction, 0.845 ± 0.186 and 0.884 ± 0.176, respectively. Measured utilities were similarly high for specific functional outcomes, even with bias corrections. Survivorship bias and skewed proportion of disease status due to natural history of PCa were potential limitations. Conclusions: Standard gamble-based utilities in long-term survivors of PCa were much higher than those determined previously. The results indicate substantial human resilience: most PCa patients adapt to their health status over time even if they experience incomplete functional recovery and would not take risk in pursuit of better quality of life. Patient summary: We elicited health utilities (measures of quality of life) among long-term survivors of prostate cancer using the most robust method. These were much higher than previously reported values that were based on theoretical scenarios or indirect methods. Long-term survivors of prostate cancer may adapt well to their health conditions over time even if they experience disease-specific or functional problems.