R packages for prospective biomarker validation with time-to-event data developed in collaboration with Yingye Zheng and Tianxi Cai.

### Estimation

**survAccuracyMeasures**: Estimate the AUC, TPR(c), FPR(c), PPV(c), and NPV(c) for for a specific timepoint and marker cutoff value c using non-parametric and semi-parametric methods. Bootstrap standard errors and confidence intervals are also computed.**survMarkerTwoPhase**: Evaluate the prognostic accuracy of a marker under two phase designs (case-cohort and nested case control designs).**survCompetingRisk**: Evaluate the prognostic accuracy of a marker with multiple competing risk events. Functions to calculate the AUC, ROC, PPV, and NPV are provided. A discrete covariate Z, if available, can be included.**survNRI**: Calculate the net reclassification index (NRI) statistic for survival data using five different estimators.

### Power Calculations

Shiny web applications to simulate power for prognostic biomarker validation studies with time to event data.