The cost effectiveness of anesthesia workforce models: a simulation approach using decision-analysis modeling

The objective of this study was to evaluate the incremental cost effectiveness of anesthesia workforce staffing scenarios, as a function of skill mix, by using the technique of decision analysis. A decision tree model was constructed to compare the incremental cost effectiveness of alternative delivery systems for anesthesia care from the perspective of the payer. Five different staffing scenarios, ranging from physician-intensive to nurse-intensive, were modeled. In the nurse-intensive model, low- and intermediate-risk patients were cared for by solo certified registered nurse anesthetists (CRNAs) and high-risk patients were cared for by physicians. In the physician-intensive model, physicians anesthetized all patients. In the first-, second-, and third-team models, all high-risk patients were cared for by physicians working alone, and all intermediate-risk patients were cared for using an anesthesia care team approach with a ratio of one physician to two CRNAs. The low-risk patients were managed by using an anesthesia care team approach with physician to CRNA ratios of 1:2, 1:4, and 1:8 in the first-, second-, and third-team models, respectively. The findings of this decision-analysis model suggest that physician-only anesthesia is not cost effective. However, the third-team model is cost effective when compared with the nurse-intensive model. IMPLICATIONS: An anesthesia care-team approach with a physician to certified registered nurse anesthetist (CRNA) ratio of 1:2 is the preferred staffing scenario for intermediate-risk patients. Although medical direction of CRNAs caring for low-risk patients is cost-effective, the small improvement in outcome resulting from increasing the physician to CRNA ratio from 1:8 to 1:4 may not be justified by the added cost.