A Categorical (Ordinal) and a Failure-Time Endpoint

In this chapter, we focus on the case when the surrogate is a categorical ordinal (or binary) endpoint and the true endpoint is a failure-time endpoint. Note that the described approach is applicable also in the reverse case, i.e., with a failure-time surrogate and an ordinal true endpoint. We mainly follow the two-stage approach proposed by Burzykowski, Molenberghs, and Buyse (2004).