The "publish or perish" phenomena is more applicable to the physical, biological, and chemical sciences and not really applicable to the medical sciences.
You would be surprised at the amount of medical (bench and clinical) research that is done that never finds it's way to a paper or that takes several years (3, 4, even 5 years) between data acquisition and paper submission.
Quite a bit of medical research is, naturally, conducted by MD's who usually have clinical responsibilities and thus are really not in a position to "perish" if they don't "publish".