Important Nurse Anesthesia Studies

Studies supporting the importance of the nurse anesthesia profession are listed below.​

Study in Health Affairs Confirms Quality, Safety of Nurse Anesthetist Care

  • Aug 3, 2010

Authors Recommend that Medicare Repeal Physician Supervision Requirement for CRNAs 

No Harm Found When Nurse Anesthetists Work Without Supervision by Physicians
Health Affairs, Brian Dulisse and Jerry Cromwell,
Abstract | PDF | Full Text

Park Ridge, Ill.— There are no differences in patient outcomes when anesthesia services are provided by Certified Registered Nurse Anesthetists (CRNAs), physician anesthesiologists, or CRNAs supervised by physicians, according to the results of a new national study conducted by RTI International. The study, titled “No Harm Found When Nurse Anesthetists Work Without Supervision by Physicians,” appears in the August issue of Health Affairs.
The RTI study examined nearly 500,000 individual cases and confirms what previous studies have shown:  CRNAs provide safe, high-quality care. The study also shows the quality of care administered is equal regardless of supervision.
Currently, the Centers for Medicare & Medicaid Services (CMS) prohibits Medicare payments to hospitals and ambulatory surgery centers when CRNAs provide anesthesia care in the absence of physician supervision. However, starting in 2001 CMS began allowing states to “opt out” of the Medicare physician supervision requirement for CRNAs. Since then 15 states—most recently California in 2009—have opted out.
The RTI findings demonstrate that the Medicare physician supervision rule for CRNAs is obsolete and unnecessary. The study compared patient outcomes in states where the supervision requirement is in place with patient outcomes in the 14 states that had opted out of the requirement between 2001 and 2005, and found that patient outcomes did not differ. “We find no evidence that opting out of the oversight requirement harms patients in any way,” said study author Jerry Cromwell, PhD. “Based on these findings we recommend that CMS repeal the supervision rule.”
"This study speaks volumes about our profession, our commitment to quality care and the proven track record Certified Registered Nurse Anesthetists have with patients across the country,” said Paul Santoro, CRNA, MS, president of the American Association of Nurse Anesthetists (AANA) in a press release distributed by the AANA. “As we have seen in opt-out states, CRNAs are highly qualified to practice in a wide variety of settings and circumstances. Whether in the operating room or in the delivery room, the data prove that CRNAs provide safe, high-quality anesthesia care.
“Motivated by the safe, excellent care that nurse anesthetists provide, 15 governors have decided to opt out of the Medicare payment rule, choosing instead to allow hospitals to make their own decisions on anesthesia staffing. This growing trend continues as states recognize the excellent skills and high-quality care of nurse anesthetists,” continued Santoro. “This study should encourage other states to think critically about their healthcare needs and how nurse anesthetists can expand access to anesthesia services.”
Other research and data support the RTI finding that there are no differences in quality of anesthesia services delivered by CRNAs and anesthesiologists. Most recently, a study about the cost effectiveness of nurse anesthetists released in May included a comprehensive review of published studies. The review found no measurable differences in the care provided by CRNAs and anesthesiologists. Equally important, the study showed CRNA-only anesthesia care to be the most cost-effective anesthesia-delivery model.
The study was conducted by Jerry Cromwell, PhD, and Brian Dulisse, PhD, for RTI International and was funded by the AANA. The study is based on 480,000 randomly selected surgical discharges from Part A and Part B Medicare data files from 1999 to 2005. The study compared adverse outcomes – specifically, mortality and complication rates – in opt-out and non opt-out states The study controlled for case complexity and patient characteristics. The authors are wholly responsible for the data, analysis, and conclusions.

About the American Association of Nurse Anesthetists 
Founded in 1931 and located in Park Ridge, Ill., and Washington, D.C., the American Association of Nurse Anesthetists (AANA) is the professional organization representing more than 50,000 Certified Registered Nurse Anesthetists (CRNAs) and student registered nurse anesthetists across the United States. As advanced practice registered nurses and anesthesia specialists, CRNAs administer approximately 43 million anesthetics to patients in the United States each year and are the primary providers of anesthesia care in rural America. In some states, CRNAs are the sole anesthesia professionals in nearly 100 percent of rural hospitals. For more information, visit The Future of Anesthesia Care Today and  follow @aanawebupdates on Twitter.

About Health Affairs
Health Affairs is the leading journal of health policy thought and research. The peer-reviewed journal was founded in 1981 under the aegis of Project HOPE, a nonprofit international health education organization. Health Affairs explores health policy issues of current concern in both domestic and international spheres.
About RTI International
RTI International is one of the world’s leading research institutes, dedicated to improving the human condition by turning knowledge into practice. The staff of more than 2,800 provides research and technical expertise to governments and businesses in more than 40 countries in the areas of health and pharmaceuticals, education and training, surveys and statistics, advanced technology, international development, economic and social policy, energy and the environment, and laboratory and chemistry services. For more information, visit RTI.