""Whereas, anesthesiologist assistants have excellent clinical safety records, are highly trained, and are authorized to provide anesthesia services under such federal programs as Medicare, Medicaid, TriCare, and the Veterans Administration; (North Carolina 2005 legislative session..))
But as far as studies showing they are safe, done in a controlled study, there are none available that I know of. But by the same token, there is no scientific evidence AAs are "dangerous" or "unsafe."
I bet if you set up a group with 10 MDAs and 10 AAs and 10 CRNAs and had the AAs and CRNAs working with the same kind of supervision, the safety of both would be equally good. (That is my hypothesis, but until it is proven or disproven it is just as good as someone else's who say AAs are not as safe.)