# Doktorandseminarium: The Nelson-Aalen estimator and some of its properties

- Date:
- Location: Ångströmlaboratoriet, Lägerhyddsvägen 1 64119
- Lecturer: Marcus Westerberg
- Contact person: Volodymyr Mazorchuk
- Seminarium

Abstract:

In survival analysis one commonly wants to study effect of treatment versus placebo on survival in a population of subjects with a specific disease. This is can done by for example comparing cumulative distribution functions that describe the probability that death has already occurred as a function of time, or hazard rates that describe the instantaneous probability of death at time t given that a subject is a live just before t. In a more general setting, one may study the time until one of possibly several types of competing events, where death is just one example of an event.

In this talk I will give a brief introduction to survival analysis in continuous time, heuristically derive the Nelson-Aalen estimator of the cumulative hazard rate function and discuss some of its properties. If time permits, I will also discuss a few extensions to the models considered.