Figure 4.

Example of a treatment choice question in the question series for eliciting maximum risk of serious bleeding patients would accept from a wearable RRT device in exchange for the benefits of the device relative to in-center hemodialysis. To estimate the maximum acceptable risk for different devices, the survey includes two sets of three risk trade-off questions, where respondents must choose between pairs of treatments: fixed reference treatment (in-center hemodialysis) and the alternative wearable RRT device as risk levels are varied. In the first set of risk trade-off questions, the respondent must choose between pairs of treatment that differ in terms of the risk of serious bleeding (as shown in the figure). In the second set of risk trade-off questions, the respondent must choose between pairs of treatment that differ in terms of the risk of serious infection (not shown). For each respondent, the survey generates a range in which the respondent’s maximum acceptable risk for switching from the reference treatment to the alternative treatment. The data from the threshold technique portion of the survey will be analyzed using an interval regression model. The coefficients from this model will allow us to determine the average maximum acceptable risk for the sample and how that maximum acceptable risk varies by patient characteristics.