Dear All,
I much appreciate your help.
I am analyzing a longitudinal survey data that collected 3 times (T1, T2, and T3). T1=600 observations, T2=500 (15%) was drop-out and T3=400 (13% was drop-out). Thus totally, 28% were a drop-out. Time-unvarying variables like sex, ethnicity did not collect in T2 and T3. An outcome of interests is a continuous variable. The main predictor is a categorical variable.
1) My inclusion criteria, I included only Subjects who had at least 2-time surveys. For instance, to exclude id_102 who missed a variable "ssup_cat" and id_107 who missed all variables. Please kindly see the attached file (I am use a SAS studio).
2) I want to create missing data files (lost to follow-up) in T1 and T2, T2 and T3 and T1 and T3.
How can I tell SAS to do the jobs. Thank you for your time in advance!
Phan S.
