In my completely unscientific and admittedly empiric observation, I will tell you my impression during this year's interview trail in the Northeast for Anesthesiology, a competitive program this year.
As some background, I was recently at a program where they told us they'd received 650-700 applications for 7 spots. In all, they are interviewing about 150 people out of those applications. I've had similar experiences at other places in the other interviews I've gone on (i.e., large apps, fewer interviews, small number of spots). One PD told us that this was a drastic change from even 5 years ago where they got maybe 40 applications out of which they did about 15-20 interviews for the same number of spots. Oh, how times have changed.
Anyway, at all of the places I've interviewed so far, I saw the Carib schools represented. At one program, I was the only Carib applicant interviewing. At the others, there were plenty of SGU and Ross students (including some people from my class I was surprised to see), a few AUC students here and there, and only one Saba student so far. I saw no students from any other Carib schools.
Draw your own conclusions from that.
-Skip