Time to tweak the TTO. But how?

This study was funded by ZonMW: the Netherlands organization for health research and development [project number 152002039] and the EuroQoL foundation. 2 This paper examines the effect different specifications of the Time Tradeoff (TTO) task have on health state values. The new lead time TTO is compared to an equally viable method called lag time TTO, both in two time frames. We test whether the two methods yield comparable health state values and whether the relative importance of dimensions of health is similarly stable between TTO specifications. The tasks were applied online and compared to results from a study with identical TTO specifications but with a different mode of administration. Lag time TTO produced lower values than lead time TTO and the difference was larger in the longer time frame. The relative importance of different dimensions of health was affected by the duration of the health state. Generally, the lead time TTO performed in group sessions gave more favorable results than the online exercise based on feasibility and data quality. 3