Whats the difference beween the Kaplan Meyer model and the Nelson Aalen one? The study notes go on about how they are similar, but are there any advantages of one system over the other?
Both use MLEs of the discrete hazard fn but in different ways. KM uses them to estimate CDF of survival fn. NA uses them, in combination with the invariance property of MLEs, to estimate the integrated hazard fn. then uses this to estimate the survival function. So I suppose the only differences are how the MLEs of the discrete hazard function are used, and the variance of the resulting estimate of the survival function.
