How can I evaluate a survival model made for interval-censored data? I'm building my models in icenReg, which only allows you to check for whether the proporitional hazards assumption is satisfied. What I'm really interested in is the predictive performance.
Harell's C index and Somers' Dxy were my first choices, but I can't find a function in R to calculate it for interval-censored data. I found a package that computes time-varying ROC curves for interval-censored models (intcensROC), from which I could calculate both the C index and Somers' Dxy, but was wondering if there was a more direct method?