There is no effect unless differences in reimbursement are introduced.
CRNA supervision does not save money for payors at least not currently.
ACTs can be used to improve physician and CRNA income in an ideal situation.
At Kaiser CRNA's could save money because it is a closed system and in theory savings to the hospital could be passed on to the health plan, but they generally aren't even cost saving even at kaiser. This is mainly because they are only cost saving at most kaiser hospitals if one have a constant 4 to 1 ratio and this just doesn't work out much of the time.
The bottom line is there is an assumption that CRNA's are cost saving. I have asked for years...for whom do they save money? It's not the payor.
Now, if you changed reimbursement so as that MD only cases were paid differently from CRNA cases then things change...but you would have to reimburse less for CRNA directed cases or more for MD's (relatively speaking).
Now, physician only groups with large hospital stipends could theoretically have their stipends placed at risk if the hospital wanted to bill for the anesthesia services and employ "providers" thinking they could save money. But this savings could be the result of employing docs, ACT or crna's alone Usually using an ACT doesn't save the hospital in an area where there are plenty of anesthesiologists.
CRNA's are expensive, especially when you need coverage during times where no billing is taking place. Docs are very cheap on call. CRNA's generally cost a fortune.
In states that have opted out, CRNA only groups can certainly compete with anesthesiologists as hospital employees. They bill for less when not directed so if they wanted to get paid 70% of a physician salary with the same call responsibilities etc, they could possibly be considered a threat.
All of this has nothing to with health care reform. Again, directed CRNA's don't save payors (e.g. insurance companies, medicare, medicaid etc.) If anyone can prove otherwise, I would love to hear about it.