Re: [R] regression with paired left-censored data

2013-04-15 Thread David Winsemius
On Apr 15, 2013, at 8:55 AM, Laura MacCalman wrote: > > HI > > I am trying to analyse data which is left-censored (i.e. has values below the > detection limit). I have been using the NADA package of R to derive summary > statistics and do some regression. I am now trying to carry out regressi

Re: [R] regression with paired left-censored data

2013-04-15 Thread MacQueen, Don
I would probably start with maximum likelihood estimation. I suppose you could impute X and Y separately using ros() from the NADA package, and then run you ordinary regression on the imputed values. Obviously, this ignores any relationship between X and Y, since each is imputed independently of t

[R] regression with paired left-censored data

2013-04-15 Thread Laura MacCalman
HI I am trying to analyse data which is left-censored (i.e. has values below the detection limit). I have been using the NADA package of R to derive summary statistics and do some regression. I am now trying to carry out regression on paired data where both my X and Y have left-censored data w