Time Trade-Off (TTO) is a method of determining the negative impact of a health problem on the patient's life. It basically indicates the number of years that the person would be willing to lose in order to live without the problem.

Patient selection: patient with a bothersome health problem



(1) time interval in years (for example, current life expectancy)

(2) number of years that the patient would be willing to trade if that would mean freedom from the health problem


TTO utility score =

= ((time interval in years) - (number of years traded)) / (time interval in years)



• minimum score: 0

• maximum score: 1

• The higher the decimal the less time that the person is willing to give up.



• There are several sources of potential bias in TTO analyses.

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