I'm fairly sure that "Classic" would be this game, since no other Theme Hospital existed before this. On the other hand I'm not sure why it needs to be called "Classic" since no other Theme Hospital exists after this either.
Compare information in the manual to the screenshots as best you can.
Well, the manual is Theme Hospital. But other documentation ie. Readme file, clearly indicates the title IS Theme Hospital Classic. At least the setup menu indicates that also: "Electronic Arts Presents CD ROM CLASSICS".
Lasted documentation indicates 1998, but some files are dated 2005.
It appears to be a re-release, since the game has been officially patched by EA. Time to send in new release info it seems.