Hi, I am trying to figure out how to estimate mean survival time in proc lifereg. It seems that I have to use a formula instead of specifying a value in "output" option, saying quantitle=? (ex. 0.5 is for median). I think for different distributions (weibull, lognormal etc), the formula for mean survival time should be different. And I have a formula for mean survival time when distribution is weibull. Is someone can help me how or where I can find the relevant formula for mean survival time under other distributions?