I'm looking to do a simple comparison of pre- and post-treatment scores on a clinical self-report measure. There are 200 patients and scores are in two variables with scores ranging from .00 - 1.00.

patient time pre post
1 Start .53 .
1 End . .81
1 Follow-up . .
2 Start 38 .
2 End . .47
2 Follow/up . .
What I'm trying to do is generate a new variable where

Pre < Post = "Improved"

Pre == Post = "Same"

Pre > Post = "Deteriorated"

..and then tabulate to get the proportion of each. What I end up doing is comparing my recorded values with the missing values.

gen effect = !.

replace effect = 1 if(pre < post)

Apologies if this is too basic a question, but I spent about three hours on this now and I'm no closer to an answer..