United States' anesthesia workdays in 2022-2023 - Implications for national workforce assessments

Over the decade from 2013 to 2023, the percentage increase in the number of anesthesia clinicians in the United States increased more than the percentage increase in the yearly number of cases involving an anesthesia clinician. A potential explanation is that the expansion of ambulatory surgery has increased anesthetizing locations on weekday mornings, thereby decreasing overall anesthetic hours per clinician. We tested this hypothesis using 2022-2023 data from the American Society of Anesthesiologist's National Anesthesia Clinical Outcomes Registry. We performed analyses comparable to those from our earlier studies using 2013 NACOR data.

We studied N = 13,901,414 anesthetics, excluding labor epidurals. Cases' start and end dates and times were used to create categories, including regular workdays (Mondays - Fridays, excluding US federal holidays) and weekends (Saturdays - Sundays). Proportions of cases were estimated along with standard errors calculated among the 26 four-week periods. A similarity index compared pairwise, between regular workdays and weekends, the relative proportions of different anesthesia Current Procedural Terminology procedure codes.

Regular workdays accounted for 95.5 % of the total anesthetic minutes. Among regular workdays, the 8-h period of 7:30 AM to 3:29 PM had 82.9 % (0.1 %) of anesthesia minutes, significantly >0.8 (i.e., ⅘, P < .0001). There were 61.2 % (0.1 %) of all anesthetic minutes completed on regular workdays and before 1:00 PM, significantly >53.0 % (P < .0001), the percentage from 2013. There were 79.2 % (0.1 %) of all anesthetic minutes on regular workdays 7:30 AM to 3:29 PM, significantly >70.3 % (P < .0001), from 2013. At least ⅔^rd of anesthetic minutes, 67.9 % (0.1 %) were covered by the 6.5 h, 7:30 AM to 1:59 PM. More than half (P < .0001) of the minutes were mornings: 51.6 % (0.1 %). There were 4.1 % (0.1 %) of case minutes on weekends, <5.2 % (P < .0001), the observed percentage in 2013. There was moderate similarity (0.511 [0.002]) between surgical procedure categories on regular workdays 7:30 AM to 3:29 PM and weekends, much <0.8, the value expected if experience with the types of procedures performed on regular workdays matched those on weekends, and < 0.55 (P < .0001), the estimate from 2013.

Nationwide, anesthesia times on regular workdays sum to substantially less than 8 h and even less than in 2013. Demand for daily numbers of clinicians at the start of the regular workdays probably is a large contributor to perceived workforce shortages and ongoing institutional support. The small but significant changes for weekends suggest an increased rationale for the development of acute care anesthesiology teams.