Important Factors that Determine Staffing Models and Strategies in Anesthesiology

Safe and efficient anesthesia staff allocation is an integral part of perioperative care. Hospitals and health systems use different strategies and staffing models that may include anesthesiologists only or anesthesiologists with resident physicians, extender trainees, and nonanesthesiologist providers, such as certified registered nurse anesthetists (CRNAs), or certified anesthesiologist assistants (CAAs). Factors that may determine anesthesia staffing model selection include patient volume, case complexity, scheduling, availability, state/local laws, institutional policies, and cost. According to the latest anesthesia workforce trends report published monthly by the ASA’s Center for Anesthesia Workforce Studies (CAWS), there are nearly 43,000 clinically active anesthesiologists (determined by Medicare billing data) in the United States (April 2024). The number of clinically active CRNAs is 51,000, and the total number of CAAs is around 3,900 (asamonitor.pub/3xInZNZ). In addition, anesthesiology residents are an important part of the clinical workforce. There are 178 anesthesiology residency training programs nationwide offering a total of 2,000 residency spots for each year of training (asamonitor.pub/3VK46y6).

Evaluating different staffing models for efficiency is important for determining current and future needs for a hospital or health system as well as financial incentives for the workforce. The evaluation of efficiency of different anesthesia care models is difficult (Anesth Analg 2003;96:1109-13). The anesthesia care team model depends on practice type, namely academic, private, corporate (national groups), and hospital-employed. Though clinical efficiency is often at the forefront when considering staffing models, it is not the only determinant of success. Consider, for example, the academic setting, where factors such as educational, training, and research activities may influence overall production (Anesth Analg 2008;107:1981-8; J Clin Anesth 2021;71:110194). In an academic setting, one anesthesiologist can supervise only two extenders when trainees (residents/fellows) are involved. On the other hand, while supervising CRNAs or CAAs, the ratio is often increased, based upon a desire to use either a direction or supervisory model. Additionally, supervision needs can change with the complexity of the cases and intraoperative critical events, namely airway issues, bleeding, or other emergent situations, which necessitates the ability to be flexible (Anesthesiology 2012;116:683-91).

In contrast, for-profit anesthesia groups adopt and adapt care models ranging from physician-only care to CRNA-only care and in between. These for-profit groups exist and thrive because they can provide much-needed services to hospitals and health care facilities, making profit in return. Numerous for-profit groups provide care in multiple states, employ thousands of clinicians, and utilize the entire range of staffing models (asamonitor.pub/45Gk4Om). These “for-profit” anesthesia groups may adapt staffing models over time to maximize profit. Anesthesia billing changes significantly with the staffing model, utilizing different coding modifiers (e.g., QK, QY) to indicate coverage levels. However, it is important to note that staffing does not always change to maximize profit and may instead be dictated by local culture, preferences, or commitments to a group or facility prior to merger or acquisition.

Case complexity, acuity, and staffing requirements warrant different staffing models. In tertiary care hospitals, anesthesia services are often required at different locations in the facility. This may include coverage for open heart surgery, neonatal surgery, anesthesia services in GI suites, and labor and delivery suites. Coverage levels often vary for different times of the day (Anesth Analg 2003;96:1109-13). Anesthesia staff providing care in some clinical scenarios may require skills – including intraoperative TEE or the ability to do peripheral nerve blocks – that will affect the staffing model. In this situation, the productivity and efficiency determination of anesthesiologists providing specialized care can be challenging.

Efficient utilization of operating suites can present a different set of challenges. Hospitals assign block time to the surgical staff based on their patient volume and convenience. If the scheduled number of patients changes on a certain day, it will result in assignment of anesthesia coverage for a location that lacks available procedural workload. On the other hand, if a location has booked more patients than the available anesthesia coverage, it may result in cancelation/rescheduling of surgical cases, causing patient dissatisfaction. Therefore, surgical site optimization is an important determinant of cost-effective anesthesia coverage. This under- or overutilization of the operating suite can occur because of inaccurate estimation of surgical durations by the surgery team and patient factors that include delayed wake-up or intraoperative events (Heath Care Manag Sci 2017;20:115-28).

Is anesthesia care better or safer in a particular staffing model? Research has shown that physician-guided care prevents excess deaths in the perioperative period and has other significant benefits such as decreasing the rates of undesired disposition following ambulatory surgery (Cochrane Database Syst Rev 2014;2014:CD010357). These facts often lead decision-makers to insist on physician-led care, as advocated not only by ASA but also the World Health Organization, in conjunction with the World Federation of Societies of Anaesthesiologists.

Five states allow nurse anesthetist-only care. While 25 states have opted out of the CMS requirement for physician supervision of nurse anesthetists, those states’ laws were not impacted that require physician oversight or involvement. Additionally, institutional and facility policies may restrict nurse anesthetist-only anesthesia through their own internal policies, safety preferences, facility culture, and past experiences. Also, there is some evidence that hiring anesthesiologists in rural areas can be difficult due to several factors (Cochrane Database Syst Rev 2014;2014:CD010357).

A reason for this may include that smaller rural hospitals are disincentivized from hiring anesthesiologists due to the federal payment program known as Rural Pass-Through. That program allows for an enhanced payment under Medicare Part A for the services of certain anesthesia providers – nurse anesthetists and anesthesiologist assistants – but not anesthesiologists. Pending federal legislation H.R. 5256, the Medicare Access to Rural Anesthesiology Act would open the program to anesthesiologists, giving them equal standing.

Mills et al. conducted a study employing semi-structured interviews of hospital administrators aimed at defining their perceptions of the safety, quality, and cost effectiveness of using different staffing models. Their findings showed that rural facilities utilized predominantly CRNA models. Staffing choice was made based on location, surgeon’s choice, and institutional factors, while anesthetic and quality and safety did not influence (or was not considered in) decision-making. A surgeon’s comfort level with the anesthesia coverage model in question has a major influence, because “it is the surgeon’s patient” and the surgeon makes the choice to bring surgical volume to one place or another, hence their influence. Administrators interviewed usually were not very familiar with anesthesia payments models (APMs). Also, most facilities in this study reported the “contracted groups over hospital/surgical site employed” model as the preferred system (Cochrane Database Syst Rev 2014;2014:CD010357).

Every hospital and surgical team has a diverse background and circumstances. Institutional norms and culture are determined by the clinician’s past experiences and training, the administration’s experience, and the financial circumstances of the hospital/institution. Institutional and personnel preferences include comfort and desire to work with or avoid working with physician extenders (CRNAs/CAAs), need for in-house coverage for trauma/OB 24/7, representation of anesthesiologists on hospital committees, and desire to work with surgical teams/providers in a certain perioperative care model (e.g., enhanced recovery after surgery (ERAS) protocols). For example, when implementing ERAS protocols, anesthesiologists play a leading role, which has shown to improve patient experience by shortening length of stay, decreasing costs, and preventing perioperative complications.

Another important factor in determining anesthesia staffing model is geographic location. There is some evidence that it is difficult to hire anesthesiologists in rural areas, while other anesthesia providers might be relatively easier to hire in rural hospitals. Availability of physician extenders is also determined by geographical location. CRNAs can be licensed in all 50 U.S. states. At present, 17 states and the District of Columbia have laws for CAA licensure, and they can work under physician license in four other states (Kansas, Michigan, Pennsylvania, and Texas). CAAs are also able to work in the Veterans Affairs (VA) health care systems, while the remaining 28 states have yet to authorize their practice. Legislation in those states may alleviate the workforce burden and improve availability of anesthesia services.

The factors that drive anesthesia staffing models at individual institutions vary greatly between provider groups. It may be difficult to perform quality research in this field. A range of factors influence the choice, including case load, complexity, specialty care (cardiac, pediatrics, etc.), institutional culture, geographic location, and, of course, the mighty dollar.