New Health Affairs Study Shows No Increased Risk of Death or Complications from Surgery When Nurse Anesthetists Work Without Physician Oversight; Authors Urge CMS to Change Rules Limiting Independent Practice
Bethesda, MD-Amid the safety debate about expanding roles for nonphysician health professionals, a new study shows that allowing nurse anesthetists to provide anesthesia services without supervision from a doctor does not put patients at risk. The study will appear in the forthcoming issue of Health Affairs, to be released on August 3.
The findings call into question a requirement that nurse anesthetists be supervised by an anesthesiologist or surgeon to receive Medicare reimbursement. States can "opt out" of the requirement, but only by petitioning CMS. The new study confirms that certified registered nurse anesthetists (CRNAs), who receive high-level training, are able to provide the same level of services as anesthesiologists at potentially lower cost.
Researchers analyzed rates of death and complications from surgery in the 14 states that "opted-out" of the requirement that nurse anesthetists be supervised by physicians. The researchers found no increase in the odds of a patient dying or experiencing complications in the states that had opted out. They also found no significant differences when they compared patient outcomes across three scenarios: certified registered nurse anesthetists working without anesthesiologist supervision, anesthesiologists working alone, or the two types of provider working together on a case.
"This study shows that patient safety was not compromised by the opt-out policy," says Jerry Cromwell, a senior fellow in health economics at the Research Triangle Institute (RTI) and coauthor of the study. "We recommend that CMS change the policy so that governors no longer have to petition for their states to opt out of this Medicare requirement," he said.
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 percent of surgeries in opt-out states and 10 percent in non-opt-out states used nurse anesthetists without anesthesiologists, as opposed to 17.6 percent and 7.0 percent 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.
Embargoed copies of this and all other studies in the August issue of Health Affairs are available to reporters. Please use username "press" and password "health" to access the page.