Hello Everyone,   I have a dataset for multiple records/ patient. Each record indicates a separate clinic visit for a certain patient identified by a unique id.   patient.     unique id patient 1-  abcd patient 2-  efgh patient 3.   ijkl   the data looks as follows    unique id   clinic visit.  Aspirin   statin abcd           1                 1 abcd           2                 1 abcd.          3 abcd           4                                1   efgh            1                                1 efgh.           2 efgh.          3                                 1   ijkl              1                1.              1 ijkl              2.                 ijkl              3                1 ijkl.             4                                   So looking at this, patients were either prescribed aspirin and statin on the same day (patient ijkl) or were only prescribe statin (patient efgh) or were prescribed both aspirin and statin but at different visits (patient abcd). My goal is to identify patients who have been prescribed aspirin and statin regardless of the visit. For clarification, I would like to identify patients abcd and ijkl in this instance. My understanding is that if I use the "if aspirin=1 AND statin=1 then var1=1..." command it will look across each record individually and not consider that those records belong to a single patient.   Happy to provide more details   appreciate your help ... View more

Hello Everyone    I have two SAS datasets    dataset 1.          dataset 2 1.                         4 2                          5 3                          6   I want to stack these on top of each other so that the final dataset looks as follows.    Final dataset 1 2 3 4 5 6   I appreciate your help. ... View more

Hello everyone, I am trying to do a DID analysis and difference in rate difference, where the rate is death rate (no of deaths/total number of infections) where death= 1/0 before and after an introduction of a vaccine (timeperiod= 0 is before and 1 is after), where vaccine= 0/1 for two different counties A and B.  For county B, the vaccine was never introduced.  I have tried looking this up but most of the examples are based on differences in means. Also since my outcome of interest is death, the population is not the same across two the time periods. Below is how my dataset looks like county  death infection  vaccine  timeperiod   A .          1 .     1 .             1              1 B .          1 .     1               0              1 A .          0 .     1               1              1 A .          0 .     1               1              1    B .          0 .     1               0              1 A .          1 .     1               0              0 B            1       1               0              0 Please let me know if more I can clarify this further.  Appreciate your help ... View more