HYE (healthy years equivalent) and TTO (time trade-off): what is the difference?

This paper demonstrates that the HYE (healthy-years-equivalent) procedure not only has nothing more to offer than the TTO (time trade-off) method, but that it introduces a systematic bias that is not present using TTO. Diagrams are used to illustrate that the HYE yields health status values, not utilities as its creators suggest, and to show that the HYE and TTO techniques are theoretically identical. Then, empirical evidence concerning the standard gamble/certainty equivalence disparity noted elsewhere in the literature is shown to indicate that HYE responses are likely to contain systematic biases that will lead to HYE estimates exceeding TTO values.