Utility valuations for outcome states of colorectal cancer

OBJECTIVE: Utilities for the outcome states of colorectal cancer (CRC) must be measured to evaluate the cost-utility of screening and surveillance strategies for this disease. We sought to measure utilities for stage-dependent outcome states of CRC. METHODS: We identified persons who had previously undergone removal of colorectal adenoma. We conducted individual interviews in which these participants were presented with stage-dependent outcome states and were asked to assess utilities for them using the standard gamble technique. RESULTS: A total of 90 participants were interviewed; nine were excluded, leaving 81 for analysis. We obtained the following utility valuations: stage I rectal or stage I/II colon cancer (mean 0.74, median 0.75); stage III colon cancer (mean 0.67, median 0.75); stage II/III rectal cancer without ostomy (mean 0.59, median 0.60), stage II/III rectal cancer with ostomy (mean 0.50, median 0.55), stage IV rectal or colon cancer (mean 0.25, median 0.20). These valuations were statistically different from each other. CONCLUSIONS: We measured utilities for stage-dependent outcome states of CRC in a sample of persons who had previously undergone removal of colorectal adenoma. We found that our participants were able to differentiate between the presented outcome states and assigned lower utility to increasingly morbid states. Our results show that stage-dependent morbidity is an important consideration in CRC and should be incorporated into any decision analysis model evaluating the cost-effectiveness of CRC screening or surveillance.