Certified Anesthesiologist Assistants (CAAs) are highly skilled health professionals who work under the medical direction of licensed physician Anesthesiologists to implement anesthesia care plans.
CAAs work exclusively within the Anesthesia Care Team (ACT) model, as described by the American Society of Anesthesiologists (ASA). Also working alongside physician Anesthesiologists in the ACT are Certified Registered Nurse Anesthetists (CRNAs).
So, what’s the difference between them? This article will take an in depth look at the education, training, licensure and recertification of CAAs and CRNAs; as well as compare the supervision, practice models, cost, billing and safety between the two providers.
Prior to admission into a CAA program, one must graduate with a Bachelor’s degree, take the required prerequisite courses in alignment with a pre-medical school track and take the MCAT or GRE. The prerequisites include higher level biology, chemistry, anatomy and physiology, as well as physics and statistics courses.
One will then attend a 24-28 month Master’s level program that is associated with an ACGME accredited medical school and has a physician anesthesiologist as the acting Medical Director.
During the program, the AA student will complete 56-132 didactic hours (program dependent) and a minimum of 2000 (avg. of 2500) clinical hours and 600 cases prior to graduation.
Similarly, CRNAs will complete a minimum of 550 cases, or 1700 hours, (avg. of 2000) and 34-80 didactic hours (program dependent) during their 24-36 month Master’s or Doctor program. Prior to entering the CRNA program, one must graduate with a Bachelor’s of Nursing and have worked a minimum of one year as a Registered Nurse in the acute care setting.
Upon graduation from either a CAA or CRNA program, the provider will have been trained in all subspecialties of anesthesia and be allowed to perform invasive line placement and regional anesthesia.
Licensing requirements are comparable for both CAAs and CRNAs. Both must obtain a license for the individual state in which they will be practicing. As of now, CRNAs may practice in all 50 states and the Veteran’s Administration, while CAAs may practice in 18 jurisdictions (including the District of Columbia and Guam) and the Veteran’s Administration.
In order to obtain a license, a CAA must graduate from a program accredited by the Commission for Accreditation of Allied Health Education Programs (CAAHEP) and Accreditation Review Committee for Anesthesiologist Assistants (ARC-AA) and pass a certifying exam given by the National Commission for Certification of Anesthesiologist Assistants (NCCAA) in collaboration with National Board of Medical Examiners.
CAAs may also practice under delegatory authority in some states; the requirements to practice are the same and both CAA licensure and delegatory authority are overseen by the state medical board. Similarly,
CRNAs must graduate from a program accredited by the Council on Accreditation of Nurse Anesthesia Programs and pass a certifying exam given by the Council on Certification of Nurse Anesthetists prior to obtaining a license.
Both CAAs and CRNAs are required to recertify throughout their careers by obtaining Continuing Medical Education Credits (CMEs) and sitting for a recertifying exam. CAAs are required to complete 40 CMEs biannually and sit for a Continued Demonstration of Qualifications (CDQ) exam every six years.
CRNAs began a two-part eight-year recertification process in 2016, during which a CRNA must obtain 40 CMES during the first four years and then sit for a recertification exam during the second four years.
Once fully certified and licensed, supervision and practice models between CAAs and CRNAs can differ depending on the practice location. As noted earlier, both are able to practice as part of the ACT under the medical direction of a physician anesthesiologist.
CAAs are recognized by the Centers of Medicare and Medicaid Services (CMS), Tri-care, and all major commercial insurance payors. CMS recognizes CAAs as qualified non-physician anesthesia providers, just like CRNAs. Under medical direction, CAAs and CRNAs are both able to practice with ratios of one physician anesthesiologist supervising four CAAs or CRNAs, according to CMS.
Whether a CAA is practicing with a state license or under delegatory authority, they practice exclusively under the medical direction of a physician anesthesiologist in the ACT model. CRNAs have the ability to practice in other models, including medical supervision by any physician (QZ) and, in some “opt-out” states, independent practice. CMS does not define supervision ratios for medical supervision.
In doing a cost-comparison between CAAs and CRNAs in the ACT, it is found that on average there is no difference because when practicing in the ACT model, billing for CAAs and CRNAs is identical for CMS and other major insurers. Requirements to be met for reimbursement are the same between CAAs and CRNAs in this model. The average annual salaries of new graduate CAAs and CRNAs are comparable at $150,00, but can differ amongst individual states.
Finally, the safety of patients is of the utmost importance and concern. In October of 2018, there was a study published in the reputable journal, Anesthesiology, that concluded “The specific composition of the anesthesia care team (whether made up of a physician anesthesiologist and an AA or a physician anesthesiologist and a CRNA) was not associated with any significant differences in mortality, length of stay, or inpatient spending.”
Overall, when practicing in the ACT model there is almost no difference between CAAs and CRNAs. In 2017, ASA republished the Statement Comparing Anesthesiologist Assistant and Nurse Anesthetist Education and Practice where they stated, “The Committee concludes that differences do exist between anesthesiologist assistants and nurse anesthetists with regard to the educational program prerequisites, instruction, and requirements for supervision in practice as well as maintenance of certification.
These are the result of the different routes that the two professions took toward development, and the stated preference of anesthesiologist assistants to work exclusively on teams with physician anesthesiologists.
None of these differences, in the opinion of the Committee, results in significant disparity in knowledge base, technical skills, or quality of care.”
Although different when broken down, hospitals that employ CAAs and CRNAs use them interchangeably as both are safe and effective members of the ACT.
- “Statement Comparing Anesthesiologist Assistant and Nurse Anesthetist Education and Practice.” Statement Comparing Anesthesiologist Assistant and Nurse Anesthetist Education and Practice | American Society of Anesthesiologists (ASA)
- Sun, Eric C., et al. “Anesthesia Care Team Composition and Surgical Outcomes.” Anesthesiology, American Society of Anesthesiologists, 1 Oct. 2018