Time trade-off utility modified to accommodate degenerative and life-threatening conditions.

The time trade-off is often argued to be the preferred utility assessment method. When measuring current health in its classic form, it involves a comparison of two certainties: perfect health and current health, each for a fixed period of time and followed by death. This makes the time trade-off insensitive to patient fears regarding premature death or worsening health. We suggest the classic time trade-off be modified to include subjective rather than actuarial life expectancy, and relaxation of the current health option to include uncertainty in quantity and quality of life. We illustrate the mechanics of this modified time trade-off and report a preliminary application to 122 men presenting to a prostate cancer screening program. Further analysis of this modified time trade-off appears warranted.