It's a mixed bag, some hospitals hire directly, and others use groups that are independent contractors to the group, in this case, the group hires both but each individual still need to apply for hospital privileges. A single anesthesiologist would probably not hire a CRNAS per se, but be a group practice. There is also the trend to very large practices groups that are nationwide to take over a hospital specialty, such as peds or the ER, and then the group hires all the staff on the provider level. This is becoming more the rule these days for costs, legalities and staffing.
It depends on what's standard where you are.
Where I am, hospitals dont employ either. We have two anesthesia groups that have Anesthesiologists and a few CRNAs. They contract with the hospital and the patient to provide services.
HMO systems, like Kaiser, employ everyone. Anesthesiologists are paid a flat salary with a small amount of production inscentive and excellent benefits. They get a lower annual pay rate in exchange for a significant retirement package.
Hospitals hire ALL the staff.
The hospital, in both cases
