Cromwell and coauthor Brian Dulisse, a health economist at RTI, analyzed 481,440 hospitalizations covered by Medicare. They found that the frequency of nurse anesthetists’ providing anesthesia without anesthesiologist supervision grew from 1999 to 2005. As of 2005, 21% of surgeries in opt-out states and 10% in non-opt-out states used nurse anesthetists without anesthesiologists, as opposed to 17.6% and 7% in 1999. The authors speculate that the increase could be due to anesthesiologists’ taking on more privately insured cases and leaving more Medicare cases to certified registered nurse anesthetists.
The researchers also found that although nurse anesthetists are trained to handle very complex cases, anesthesiologists, on average, work on more of these cases, which involve greater risk of death. The authors hypothesize that anesthesiologists, who can choose their cases more often than can certified registered nurse anesthetists, prefer more complex, better-paying, cases. Anesthesiologists also are more prevalent in teaching hospitals that perform more complex surgery.
“Nurse anesthetists get essentially the same training in anesthesia as anesthesiologists. So in this case, a nurse is just about a perfect substitute for the doctor,” says Cromwell. “Eliminating physician supervision will not only allow nurses to do what they are trained and highly qualified to do, but it will encourage hospitals and surgeons to use a more cost-effective mix of anesthetists.”
Using nurse anesthetists more broadly could help save on health care costs because they typically earn less than anesthesiologists, the authors say.