Right to the problem, I need to model time-to-event in a sample with a good number of left- and some interval-censored cases. My impression is that I can't use Cox or proportional hazards regression? Am I right? If that's the case can anyone give me some references I could use to find out what type of analysis is the most appropriate? Thanks in advance Pablo BTW, Thanks to all the people who kindly answered my email regarding survey software.