[R] package to do inverse probability weighting in longitudinal data

[Lei Liu]

Hi there,

I have a dataset from a longitudinal study with a lot of drop-out. I 
want to implement the inverse probability weighting method by Robins 
1995 JASA paper "Analysis of semiparametric regression models for 
repeated outcomes in the presence of missing data". Does anyone know 
if there is a package to do it in R (or other software)? Thanks a lot!

Lei