I am doing survival analysis on a dataset where the number of right-censored individuals is much greater than the number of observed individuals. There are about 50,000 individuals and only about 5,000 of them are observed. So as you might imagine, the survival curves are not that informative because they never go below about 80%.
So I was wondering what the implications would be by looking at only the observed data (i.e. the 5,000). I would imagine that this would artificially lower survival probabilities on the curve. However, if you are only interested in the relative difference in survival curves for different groups (I am using a regression-based SA model, where the different groups are defined by different values of the covariates) would it matter?