In health economics, time trade-off (TTO) is a technique used to measure the quality of life that a person or group is experiencing.
An individual will be presented with a set of directions such as: Imagine that you are told that you have 10 years left to live.
For example, an individual with severe asthma could be offered 10 years in their current condition, or a shorter length of time in full health.
In this case, the individual would have valued living with severe asthma at 0.8, relative to full health (defined as 1.0).
[3] Time trade-off results are often used to calculate quality-adjusted life years (QALYs), allowing healthcare decision makers to combine mortality and morbidity into a single interval scale.