When analyzing a lognormal data with left-censored values using a regression model, I have read that you can use methods that fit right-censored data but “flip” the data by subtracting from some large constant. Why does this work? Why are the coefficients the same?
This link describes the NADA package: "The routines in NADA for R internally flip the original data by subtraction from a large constant, in order to produce right-censored values that can be input to survival analysis routines."
The survreg library in R has the option for "type=left", but I am not clear on the correspondence, and I would like to see the equations and make survreg match NADA.