Anesthesia Services: A Workforce Model and Projections of Demand and Supply

Sebastian Negrusa, PhD; Paul Hogan, MS; Inna Cintina, PhD; Jihan Quraishi, MS, BSN, RN; Ruby Hoyem, PhD; Lorraine Jordan, PhD, CRNA; Matt Zhou, MS


Nurs Econ. 2021;39(6):275-284. 

In This Article

Abstract and Introduction


Anesthesia services in the United States are undergoing rapid transformation, pointing to substantial changes in anesthesia delivery and need for anesthesia services. Understanding the demand and supply of anesthesia services is necessary to predict and plan for adequate patient care services. In an anesthesia workforce model, a current 10.7% excess demand is estimated. The excess demand will decline to 3.6% by 2027. Swiftest reductions in excess demand are achieved by increasing new entrants and shifting delivery models toward providers acting independently.


Anesthesia services in the United States are undergoing rapid transformation due to an aging population, greater practice consolidations, decisions to support value-based care (Provident Healthcare Partners, n.d.), and trends toward more anesthesia services in outpatient settings (Osman & Shapiro, 2019). These factors point to substantial changes in anesthesia delivery and the need for anesthesia services. Future demand and supply of anesthesia services are assessed in this analysis.

Healthcare workforce projections inform workforce development and training programs, promote care in underserved areas, and guide regulatory policy related to scope of practice (SOP) and reimbursement (Wing et al., 2016). Current and projected future market for anesthesia services were analyzed. Relationships between demand and supply and their determinants, such as demographic mix, interactions between anesthesia providers under the various delivery models, and other specific aspects related to anesthesia delivery, were measured. Population needs are at the center of the demand side of workforce models and projections. An economic approach to demand is used, in which projected demand is based on both patient needs and the ability to finance them through public and private insurance, and other sources of financing. A workforce model was constructed based on these estimated relationships, using a method that allows for possible shortages or surpluses in the baseline year. This model was used to forecast the state of the anesthesia market in the future under a baseline scenario and several hypothetical scenarios.

Anesthesia services are provided by anesthesiologists, certified registered nurse anesthetists (CRNAs), and anesthesia assistants (AAs). Anesthesiologists personally provide services or can supervise or direct CRNAs or AAs. Under medical direction, an anesthesiologist directs one to four CRNAs or AAs and is present at specific stages of the procedure. Under supervision, an anesthesiologist supervises CRNAs at a facility but is not necessarily present during the procedure. While AAs must work under anesthesiologist direction, CRNAs can also provide services without supervision depending on SOP laws and facility policy. The delivery model by which services are provided – whether anesthesia is provided by CRNAs or anesthesiologists practicing without direction or in a team model that includes medical direction or supervision – affects provider productivity and, ultimately, costs. Direction models tend to be costlier than CRNA autonomous practice, likely contributing to recent increases in anesthesia provided by CRNAs practicing without direction (Cintina et al., 2018).

Frogner and coauthors (2020) noted that most health workforce models follow a silo-based approach based on the assumption that each health profession has an exclusive and fixed scope of practice. They call for healthcare workforce studies that place a greater emphasis on patient needs rather than on forecasting the "right" number of each type of health professional needed in the future. In this study, the overlapping SOPs of CRNAs and anesthesiologists are acknowledged, unlike previous provider-centric studies that describe shortages of CRNAs as distinct from shortages of anesthesiologists (e.g., Daugherty et al., 2010). CRNAs and anesthesiologists can work independently, as well as together, under the four delivery models discussed. Projections provided by this study are thus likely to be more relevant for policymakers and regulators looking to maximize value for patients and healthcare systems, as all anesthesia providers are considered collectively, along with their interrelated dynamics of team-oriented delivery of care.

Negrusa and colleagues (2016) found no difference in the complications rates following anesthesia when CRNAs practiced undirected, compared to anesthesiologists practicing independently. Also, IHS Global (2020) showed that when assuming greater substitutability between advanced practice registered nurses (including CRNAs) and physicians lowers provider shortages in the future. The present study also offers an innovative approach to healthcare workforce analyses by building forecasts on a measure of shortages or surpluses in the current period, rather than on an assumed equilibrium between demand and supply, as in many past studies (e.g., IHS Global, 2015). The present study uses the most recent estimates of workforce entry and exit rates.