From the April 2003 newsletter
More than half of the candidates failed the written in 2000. That to me is pretty suggestive that the written exam has a knowledge threshold for passing; perhaps you think it is "culturally biased" because so many anesthesia programs filled with FMGs in the late 90s? You don't have to leave this forum to find people who think the written is an unnecessary, arbitrary test of clinically-irrelevant minutia - they're entitled to their opinion, but I respectfully disagree.
Oral pass rates in those years+1 were a little better, in the 70% range. I think this is evidence that the written exam is pretty good at weeding out knowledge-deficient candidates ... but not perfect. What's more, the 10% lower-than-usual oral pass rate is evidence that an oral exam is needed to catch some of the weak candidates who managed to scrape by the written.
A cynic might argue that the reason more people failed the oral those years was because there were more FMGs in anesthesia, and the racist examiners kept them out. I think that's a ridiculous accusation that needs solid evidence to make, and that a more reasonable explanation was that a lot of candidates those years were simply sub par ...
and the oral exam functioned as intended by denying board certification to them.
Old thread on this subject, though that thread is more focused on the written exam. I won't repost what I wrote there; the arguments are the same. Reasonable people can (and do) disagree with me, but when it comes to fairness, I think the ABA does a good job with the absolutely necessary board certification process.