'Lead Time' TTO improves upon conventional TTO by providing a uniform method for eliciting positive and negative values. This research investigates (i) the values generated from different combinations of time in poor health and in full health; and the order in which these appear (lead vs. lag); (ii) whether values concur with participants' views about states; (iii) methods for handling extreme preferences. n = 208 participants valued five EQ-5D states, using two of four variants. Combinations of lead time and health state duration were: 10 years and 20 years; 5 years and 1 year; 5 years and 10 years; and a health state duration of 5 years with a lag time of 10 years. Longer lead times capture more preferences, but may involve a framing effect. Lag time results in less non-trading for mild states, and less time being traded for severe states. Negative values broadly agree with participants' stated opinion that the state is worse than dead. The values are sensitive to the ratio of lead time to duration of poor health, and the order in which these appear (lead vs. lag). It is feasible to handle extreme preferences though challenges remain.

Background: The estimation of Quality Adjusted Life Years gained from treatment requires length of life to be quality adjusted by the weight ('value') attached to the quality of life in each health state. These weights are anchored on a scale of 1 for full health and 0 for dead, with health states considered to be so bad that they are worse than being dead, having negative values. A widely used method for obtaining these values is the 'Time Trade Off' (TTO). The National Institute for Health and Clinical Excellence (NICE), for example, recommend the use of TTO values in evidence submitted to it on the cost effectiveness of new technologies. However, there are some important problems with TTO. These problems centre on the inability of the method adequately to handle very poor states of health, which people may consider to be worse than dead. Where that arises, the TTO has to switch to a different questioning process, with corresponding problems for the comparability and interpretation of values in the negative range. In previous research, we tested a new TTO approach, the 'Lead Time TTO', which is capable of producing weights both for states better and worse than dead in a uniform manner. Aims: The aims of this research are (i) to investigate the values generated from Lead Time TTO (LT-TTO) using different combinations of the duration of the health state and the time in full health which participants are asked to consider; as well as varying the order in which these appear (Lag Time TTO); (ii) to gauge if values generated from these methods concur with participants' views as to whether the states are better or worse than dead (iii) to explore a range of methods for handling the preferences of those whose distaste for very poor health states is such that they 'use up' all their lead time. Methods: A sample of 200 members of the general public valued five health states, using two of four variants of the LT-TTO: a lead time of 10 years with a health state duration of 20 years; a lead time of 5 years and a health state duration of 1 year; a lead time of 5 years and a duration of 10 years; and a duration of 5 years with a lag time of 10 years. Participants also responded to a range of supplementary tasks and other questions. Results: Values are influenced by the length of the lead time relative to the health state duration. Longer lead times enable somewhat more preferences to be captured, but appear to exert a framing effect on values. Lag time TTO results in less non-trading for mild states, and to participants trading off less time for severe states. Of those who valued the worst health state as negative, 70% also expressed the view that this state was worse than dead. Conclusions: LT-TTO confers an important advantage over the traditional TTO by providing a single method capable of generating positive and negative values that seem broadly in keeping with participants' stated views about those states being better or worse than dead. However, values are sensitive to the length of time in full health relative to the d...

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Many medical devices offer improvements over current care that may be difficult to assess using standard methods of economic benefit measurement such as the quality-adjusted life-year (QALY). The objective of this research was to explore the extent to which these benefits have been measured and valued by alternative approaches, such as willingness-to-pay studies or discrete choice experiments. We undertook a systematic review of the literature from 1996 to 2013 to identify empirical studies on the benefits of medical devices using the alternative methodologies. The search resulted in 2772 hits, of which 2016 were considered not relevant to the study and 76 were duplicates. After further examination, there were 30 relevant empirical studies, of which 18 were willingness-to-pay and 12 discrete choice experiments. This research demonstrates that while it is feasible to measure and value the attributes of devices using alternative approaches to standard quality-of-life measures, the literature is quite limited when compared with that for non-device technologies.