Time to death (TTD) health state utilities have been extensively used in immune-oncology, and generally estimated using discrete ‘groupings’ of TTD, typically in days or months to death.

The TTD approach can be generalized to use continuous functions of TTD, avoiding the need for strong assumptions regarding the construction of groups. The results show an improved model using fewer assumptions/variables.

TTD analysis generates consistent results across different regions and EQ-5D country tariffs, with a clear pattern of decreased utility in the final year (and particularly, the last 3 months) of life.