[R] How to analyze observations list-wise deleted?

[Chengshan Liu]

I am using lrm in Design package for a project using logit analysis.
I think lrm is very useful for providing information about the number of
missing values due to the inclusion of each variable.

My first questions is: How to explore those observations that are
automatically deleted from the lrm?
For example, in a data I have more than 6,000 observations but after
list-wise deletion I have only 2,411 observations, where there are 583
observations for the dependent variable of value 1 and 1,828 for the
value 0.

One independent variable of the model "cDisagLW" accounts for the
deletion of 2,598 observations and I think this could cause problem in
regression result. So, could you show me a way to find out "who" are
those 2,598 observations?

A further question is, how to make a subset of the original data that
contains these 2,411 valid observations?
With this dataset, I like to explore the underlying distribution of the
regression data and contrast to the original data of 6,000 observations.

Thank you in advance.

Frank

-- 
Frank C.S. Liu
Assistant Professor,                      
Graduate Institute of Political Science   E-mail: frankcsliu at gmail.com
National Sun Yat-sen University (NYSYU)   Office:+886.7.525.2000 #5555
Kaohsiung, Taiwan 804, R.O.C.             FAX:+886.7.525.5540