It's an interesting point, not just the placement rate but the graduation rate for medical schools is very high (barring a few last-chance, offshore type places if I understand correctly).
I never did it but have watched the process from a few different viewpoints. My impression is that the gatekeeping on the entry side is pretty strong (not just exam results, good schools may have multiple interviews before letting you in) but they also have ton of resources available to help you if you are bogged down. This latter part is helped by high tuition.
As for the vetting, as far as I can see they are fine with a bunch of false negatives, which results in more homogeneity than may be desired. It doesn't seem to be particularly empirical.
I never did it but have watched the process from a few different viewpoints. My impression is that the gatekeeping on the entry side is pretty strong (not just exam results, good schools may have multiple interviews before letting you in) but they also have ton of resources available to help you if you are bogged down. This latter part is helped by high tuition.
As for the vetting, as far as I can see they are fine with a bunch of false negatives, which results in more homogeneity than may be desired. It doesn't seem to be particularly empirical.